



Buy anything from 5,000+ international stores. One checkout price. No surprise fees. Join 2M+ shoppers on Desertcart.
Desertcart purchases this item on your behalf and handles shipping, customs, and support to Lithuania.
๐ Unlock hidden conversations with pro-level precision!
The F999B Super Sensitive Listen Thru-wall Contact/Probe Microphone Amplifier System is a professional-grade surveillance tool designed to detect sound through solid surfaces like concrete, metal, and wood. Featuring a highly sensitive quartz crystal piezo microphone, 4 selectable audio channels, and up to 20,000x amplification, it offers continuous 24-hour monitoring powered by a rechargeable lithium battery. Its rugged metal housing ensures durability, while the private listing option guarantees discreet purchasing. Ideal for serious users needing reliable audio detection through walls and doors.
| ASIN | B01L9AMY9Y |
| Antenna Location | Investigation, Surveillance |
| Audible Noise | 70 Decibels |
| Audio Sensitivity | 70 Decibels |
| Best Sellers Rank | #230,534 in Electronics ( See Top 100 in Electronics ) #1,429 in Audio Component Amplifiers |
| Brand | Kstpower |
| Built-In Media | amplifier, battery, warranty card |
| Color | silver |
| Compatible Devices | ['Smartphone', 'Laptop', 'Personal Computer', 'Tablet', 'Camera', 'Headphone', 'Radio', 'Speaker', 'Karaoke Machine', 'Amplifier', 'Gaming Console'] |
| Connectivity Technology | Auxiliary |
| Connector Type | 3.5 mm Jack |
| Customer Reviews | 3.4 3.4 out of 5 stars (26) |
| EU Spare Part Availability Duration | 5 Years |
| Enclosure Material | Wood |
| Frequency Response | 20 KHz |
| Impedance | 32 Ohms |
| Item Dimensions | 9.06 x 7.09 x 2.76 inches |
| Manufacturer | Kstpower |
| Mfr Part Number | F999B |
| Microphone Form Factor | Mini |
| Model Name | F999B |
| Model Number | F999B |
| Number of Channels | 4 |
| Polar Pattern | Omnidirectional |
| Power Source | Battery Powered |
| Signal-to-Noise Ratio | 70 dB |
| Special Feature | 3.5mm jack |
| UPC | 723800422475 |
A**N
Great Basic Device
Reading others views here, I thought I would add my own opinion. Definitely a Chinese manufacture, and quality is so-so. Packaging and case quality are frankly horrible. That said, I am loving this device. Do not try to hold the probe manually; you cannot keep it still enough for decent signal. Nor can you tape to wall firmly enough. Find or create a flat surface to adjoin the wall - such as a large, flat book. Then find something nonmetallic and HEAVY to press against the fixture to create non-moving firm contact. The sound quality isn't what you would get from a mic inside the target area - but it is VERY close. I use an Olympus LS-P2 recorder that has two 3.5 openings - one for external mic and the other for a standard headphone. I tried buying a cheaper Olympus MP3 recorder for dedicated use with this mic, but it didn't process the incoming signal well; so you really have to get a decent recording unit assuming you do intend to connect the unit to a digital recorder. The unit also has several ports - FM transmitter (which I don't use), DC Charging port, Mic (for wall probe), REC - direct connection to your digital recorder and EAR - for headphones. So you can monitor the recording either through the device or through your recorder. As far as the 'do not overcharge' message - Ok, that's a bit unusual, but I just recharge when I am on hand to monitor it occasionally; it's probably not something you want to run off and leave. When the light turns green, it's done and you can unplug - not a big deal IMO and certainly not a dealbreaker or anything justifying less stars or a neg review. By the way the battery life is great. I had to leave this on for about 8 hours unattended and the unit worked very well. My advice is shop around. As good as this is, it is clearliy 80s/90s tech; it's enough for my use, but there are probably better things out there albeit more expensive. $105 for this kit is completely justifiable.
D**N
product critique
satisfied
A**R
Piece of crap doesn't work at all don't buy
Doesn't work a clear ripoff don't buy from this company or seller
Z**N
Four Stars
Good stuff easy to handle.
B**.
Trash doesnt work, wast of money,worthless
there's nothing to like the xxx thing does nothing
L**R
Works very well! Finding leaks! :-)
While I did not use it for its intended purpose, I got this to help me find a leak in the wall, I got the idea from someone on Youtube. One can set the frequency and found a water leak before it became a horror story. Took a bit of getting used to it. But a steady had to hold the probe and patiences came within a few inches of the source of the sound. (Note slow drips are harder) But this was a streamer..... Definitely a nice thing to add to the toolbox.
Trustpilot
1 week ago
1 month ago