Most frequent questions and answers









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Terminal adapter

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Operation terminal

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Terminal cable

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Post-processing system

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Power adapter

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Portable earphone

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Tripod bag

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Denoise headset

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Transportation case

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Manual PTZ

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Power switch

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Host antenna

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Electric PTZ

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User Manual

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Electric PTZ cable

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Packing list


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Post-processing key

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  • Laser sources are infrared lasers. Different from normal visible light source, laser source is compact, low discrete and invisible to human eyes. Strictly forbidden to look directly into the lens while working
  • No radiation to operators and environment


Environment temperature

Relative humidity

Ambient pressure




Atmospheric pressure

  • Store the case and the equipment in a dry place with the front side facing upwards. Do not sit or lie on the packing case.
  • Do not place the equipment in a random manner.
  • Do not touch the host lenses with your hands.

We sell only to Law Enforcement Agencies or Government Agencies.

It’s wireless transmission.

Yes, the operating terminal is Using Android operating system, screen size ≥6.5 inches.

First Medium:
Tissue box, cigarette box, paper cup, foam board, wall publicity board, etc. Listening effect of first medium is the best,in turn,the effect gradually weak.

Second Medium:
Bag, clothes, curtain, plant, chair back,sofa,etc.

Third Medium:
Wall switch, photo frame, file cabinet, air conditioner, car, plastic trash can ,etc.

Sound information can be obtained through multi-layer glass windows at a large angle.

A variety of noise reduction functions, with high sound recognition and reading comprehension.

Multi-functional mobile operation terminal is wirelessly connected with the host, “viewing, aiming, listening, recording and transmitting” in one to realize remote control operation.

Our laser listening device has good night vision capability.

Rapid assembling, simple operation, one key start-up and focusing, enter working state within 1 minute.

Yes, we can provide the training services for our users and due to the Covid restrictions. We conduct the training online. and we don’t charge you separately. 

Our laser listening device does not come cheap and for more questions about pricing, please either contact with our distributor or send us an inquiry.

Our laser microphones are usually not susceptible to  weather conditions.

It is possible for us to arrange a system demo either at our company or at your premise. But our location is preferred due to Covid restrictions.

System demo is not free of charge and we may charge you for a fee for the demo. 

The application scenarios of fingerprint unlocking technology are very wide, and the range of electronic products involved is very rich, including not only the current mainstream smart phones, but also access control, attendance machines, safes, cars, laptops, smart door locks, etc. The application direction covers data protection, identity login verification, application payment, mechanical opening and so on.
The development of fingerprint unlocking technology has roughly gone through three eras. So far, sensitivity, security, and anti-counterfeiting technology have become very reliable in the iterative process.
So today, based on some recent experimental situations, we will talk about the technology of fingerprint unlocking in depth. Why should we talk about fingerprint unlocking again? Before, our forensics workers were dealing with power-on passwords and could not pass the technology. Unlocking or technical unlocking technology is extremely difficult to implement and the risk is extremely high to use the method of imitating the fingerprint of the suspect to unlock, which can substantially promote and help some qualified cases, but at present, it is only for smartphones. There are indeed some limitations to the study of fingerprint unlocking technology. The application of fingerprint technology is widely used. In many cases, it is meaningful to use fingerprint unlocking. Then, using fingerprint unlocking faces several major problems: 1. Where is the fingerprint source? 2 .The problem of fingerprint source accuracy correction
1. Application distinction of the main fingerprint unlocking technologies:
There are many types of fingerprint unlocking technologies, but at present, only three fingerprint unlocking technologies are used in the most extensive scenarios and scopes:
1. Semiconductor capacitive fingerprint

Semiconductor capacitive fingerprint is the current small, miniature and low-cost capacitive fingerprint solution. The fingerprint module is small in size and can be embedded in places such as mobile phone navigation keys, U disks, laptop switches, smart door lock handles, etc. It can be said to be the most widely used. It is also the earliest fingerprint unlocking technology introduced by smartphones. The principle of capacitive fingerprint technology is similar to that of capacitive screens. The fingerprint bump will form a capacitance difference between the part that touches the surface of the fingerprint module and the part that is not in contact with the dent, forming a fingerprint image.

2. Under-screen optical fingerprint
The optical fingerprint under the screen is a fingerprint recognition technology that has only been widely used in the past two years. Most of them have been applied to smartphones. The principle is that the fingerprint recognition module is actually a miniature camera, which can self-illuminate through the OLED screen. , Illuminate the fingerprint on the surface of the screen, and the reflected light passes through the OLED screen and is collected by the camera under the screen to form a fingerprint image. Perhaps due to the high cost of the technology itself, no other products have yet been found to use this technology on a large scale.
3. Reflective Optical Fingerprint
The principle of reflective fingerprint and under-screen fingerprint is similar, but it is not a camera, but it can also be regarded as a very simple camera. The reflective optical fingerprint technology is earlier than any other fingerprint technology, but the reflective optical fingerprint module is generally larger in size. It is not suitable for small portable devices, and is widely used in some larger and fixed devices such as attendance machines and smart door locks.
In addition, there are a series of more advanced and more difficult to counterfeit fingerprint technologies such as ultrasonic fingerprint technology and subcutaneous capillary fingerprint technology.
2. Fingerprint storage has certain fault tolerance
This problem was discovered by our team during the laser fingerprint making experiment. The team’s developers changed the size of the fingerprint from the actual 15.2mm*20.3mm to 15mm*20.05mm by mistake, that is to say, the production Compared with the real fingerprint, the fingerprint mold produced is smaller, but the mobile phone can still be unlocked with this fingerprint mold. Moreover, after many experiments, larger and smaller ones can be used. Capacitive fingerprints are better than under-screen optical fingerprints. The allowable error is larger. Before that, we all agreed that the fingerprint requires 1:1; but this is not the case.
Another phenomenon, the mobile phone we tested a year ago recorded the fingerprint of a developer in our team, and recently took it out for a fingerprint recognition test, and found that the real finger could no longer be recognized, but the fingerprint made a year ago was There is no problem, normal recognition, that is to say, there has been an error between the fingerprint made a year ago and the current finger, of course, the change of the finger, what is more interesting is that after dozens of attempts with the finger at different angles, finally It was successfully recognized once. Since then, the finger can be successfully unlocked by using the finger again. It is guessed that the high probability is due to some changes in the shape of the developer’s finger over the past year, which exceeds the fault tolerance of the fingerprint. Scope, in the process of constantly changing the angle and direction, due to the existence of the extrusion situation, the fingerprint can be verified and recognized normally, and the smart phone may also correct this situation through some algorithms (just speculation, no actual theoretical basis) . We reproduced this situation through fingerprints. By making a fingerprint with a large error that cannot be correctly identified, and then testing from multiple angles, it was correctly identified after dozens of attempts. From the beginning, the finger The model can be successfully identified later. (This test is only carried out on a certain brand of Android mobile phones, and no large-scale test has been carried out, and the generality is not yet known.) It can be proved that some fingerprint recognition devices have tolerance and the ability to correct fingerprint data from time to time, which means that for The use of fingerprint unlocking technology by case investigators will be more extensive, and the applicability will be stronger. (Of course, more experiments are needed to verify this, because from the manufacturer’s point of view, the consequences of the user’s inability to unlock with fingerprints are more serious, as you all know)
3. Biological characteristics of fingerprints
Now basically all are biometric fingerprints, that is to say, those without biological characteristics cannot be recognized normally, but the reality is that the so-called biological characteristics are the difference in capacitance. The bioelectricity we are talking about means that the human body has bioelectricity before it can be used. Finger to verify the fingerprint, this bioelectricity is actually the root cause of the capacitance changes in different areas on the surface of the fingerprint device, such as a dead body, which does not have bioelectricity after a long time, and the capacitance difference is relatively small, and it is not easy for the fingerprint identification device to generate a fingerprint image.
Secondly, some fingerprint recognition modules have the function of color recognition. Because the fingers are flesh-colored, if you paint them all black, they cannot be recognized normally. They are also defined by the manufacturer as a biometric feature. I think this is the stupidest biometric feature.
4. Collection of deformed fingerprints
After the death of the human body, the bioelectricity disappears, and the existing fingerprint entry tools are not very useful (of course, we have developed a corpse-oriented fingerprint rapid entry identification tool for this situation). Fingerprints (such as fingerprint collapse, soaking and swelling), but once the degree of deformation is high, the error between the fingerprint collected by the extension method and the actual fingerprint is large and cannot be used, but the fingerprint image is collected by the pure optical fingerprint module, and then the image The software tries to repair. If the fingerprint skin has become dry and hard and cannot fit the fingerprint module, it is necessary to soak the fingerprint with medicine (of course, the collection of fingerprints can refer to criminal investigation methods. We, as epigenetics, are also learners)