--- product_id: 40506837 title: "New F999B Super Sensitive Listen Thru-wall Contact/probe Microphone Amplifier System (Warranty period of five years)" brand: "kstpower" price: "921.53 DT" currency: TND in_stock: true category: "Kstpower" url: https://www.desertcart.tn/products/40506837-new-f999b-super-sensitive-listen-thru-wall-contact-probe-microphone store_origin: TN region: Tunisia --- # 3.5mm stereo headphone output 20000x max gain amplification 24h continuous battery life New F999B Super Sensitive Listen Thru-wall Contact/probe Microphone Amplifier System (Warranty period of five years) **Brand:** kstpower **Price:** 921.53 DT **Availability:** βœ… In Stock ## Summary > πŸ” Hear what others can’tβ€”unlock hidden conversations with pro-grade clarity! ## Quick Answers - **What is this?** New F999B Super Sensitive Listen Thru-wall Contact/probe Microphone Amplifier System (Warranty period of five years) by kstpower - **How much does it cost?** 921.53 DT with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/40506837-new-f999b-super-sensitive-listen-thru-wall-contact-probe-microphone) ## Best For - kstpower enthusiasts ## Why This Product - Trusted kstpower brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Discreet & Durable Design:** Metal housing ensures rugged reliability for professional-grade use. - β€’ **Plug & Play Compatibility:** Seamlessly connects via 3.5mm jack to smartphones, laptops, and more. - β€’ **All-Day Surveillance Ready:** Continuous 24-hour monitoring powered by a robust 3.7V lithium battery. - β€’ **Unmatched Wall Penetration:** Hear through cement, metal, wood, brick & more with supreme sensitivity. - β€’ **Quad-Channel Audio Precision:** Four frequency channels (1200Hz, 800Hz, 200Hz) for crystal-clear sound clarity. ## Overview 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 20000x amplification, four audio channels, and up to 24 hours of continuous battery life, it delivers superior sensitivity and durability in a compact metal housing. Ideal for discreet monitoring, it connects easily via 3.5mm jack to a wide range of devices and comes with a 5-year warranty for peace of mind. ## Description The ultimate professional listen through wall system that can hear sound through concrete, metal, wood, brick in fact any solid surface. This serious piece of kit is not for the faint hearted, be warned you can hear through indoor and outdoor walls. Some surfaces work better than others and density / thickness can also restrict its performance. We have received varied results as it depends entirely on the surface you use and many other factors such as distance and volume. Place the Sonde contact microphone to the surface of interest and listen it has variable gain and volume settings. You may need to experiment further with the position for better results and we can not guarantee results first time every time. We guarantee it will hear audible sound through any door or single brick / cavity walls. Anything else is not guaranteed and returns for using this beyond it's means is not accepted. Unless it is faulty not hearing through doors, windows, internal walls etc. Another serious matter is the headphones used, included is good quality earbuds but if you use noise cancelling headphones costing Β£50-Β£200 this improves the sound hugely. F-999B professional listen through wall spy ear is a highly sensitive contact and probe microphone amplifier system. Both microphone and amplifier are built into a strong metal housings for durability. Enhanced quality sound and performance capable of listening to conversations in adjoining rooms and houses. High quality earbuds a built in lithium battery and all accessories needed to achieve the job. The highest sensitive contact microphone available with superior detection ability using best quartz crystal piezo. This quality component is more sensitive and clearer than anything else out there and if this does not work then nothing will for less than Β£100. Package includes: Sonde contact microphone Probe / Needle microphone Microphone / Headphone Amplifier 2.5mm-3.5mm stereo record lead Charger and Metal case ## Features - HIGHEST SENSITIVE LISTEN THROUGH WALL / CEILING CONTACT & PROBE MICROPHONE SET - THIS IS A PRIVATE LISTING DUE TO THE NATURE OF THIS PRODUCT. YOU CAN PURCHASE THIS PRODUCT AND IT WILL NOT SHOW UP ON YOUR FEEDBACK PROFILE. - Penetrable surfaces: Cement, Metal, Wood, Iron, Glass, Plastic, Brick Working time: Continuos monitoring up to 24 hours Headphone output: 3.5mm stereo @ 250mW Four audio channel: 1200Hz, 800Hz, 200Hz - Maximum gain amplification: 20000 times Battery type: 3.7v lithium battery Microphone sensitivity: -70db Current consumption: 10mA - Record line output: 2.5mm stereo Jack socket Battery capacity: 250mA ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B01L9AMY9Y | | Antenna Location | Investigation, Surveillance | | Audible Noise | 70 db | | Audio Sensitivity | 70 db | | Best Sellers Rank | #295,800 in Electronics ( See Top 100 in Electronics ) #1,637 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 ohm | | 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 | ## Product Details - **Brand:** Kstpower - **Color:** silver - **Connectivity Technology:** Auxiliary - **Connector Type:** 3.5 mm Jack - **Included Components:** amplifier, battery, warranty card - **Model Name:** F999B - **Polar Pattern:** Omnidirectional - **Recommended Uses For Product:** Investigation, Surveillance - **Special Feature:** 3.5mm jack ## Images ![New F999B Super Sensitive Listen Thru-wall Contact/probe Microphone Amplifier System (Warranty period of five years) - Image 1](https://m.media-amazon.com/images/I/516u180BZNL.jpg) ## Questions & Answers **Q: can this be used to listed to heartbeat like a stethescope?** A: Don't fit **Q: can it record?** A: No Unfortunately **Q: how come i was sent a 929 when a f999b is what i should have gotten, all over this page says f999b,invoice says f999b, it dosnt seem fair** A: As some one who just got fired from Amazon I think you get a refund and buy it at any place as long as its not Amazon. **Q: How far can you be from the microphone and still hear?** A: Never worked, and the cost to send it back, and paperwork, is understandably why they can sell defective products, and not have to worry about refunds, or merchandise returns. Totally Dissatisfied ## Frequently Bought Together - New F999B Super Sensitive Listen Thru-wall Contact/probe Microphone Amplifier System (Warranty period of five years) - Shure SM58 Pro Dynamic Microphone with 25-Foot XLR Cable - Professional Studio & Live Performance Cardioid Mic for Vocals, Podcasting, and Recording (SM58-CN) - Shure SM57 Pro XLR Dynamic Microphone - Professional Studio & Live Performance Cardioid Mic for Instruments, Recording for Drums, Percussion, & Instrument Amplifier Miking (SM57-LC) --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.tn/products/40506837-new-f999b-super-sensitive-listen-thru-wall-contact-probe-microphone](https://www.desertcart.tn/products/40506837-new-f999b-super-sensitive-listen-thru-wall-contact-probe-microphone) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-09-09*