It transmits sound by your throat vibration rather than microphone. Effectively avoid environmental noise and make the call clearer. With the best-quality transparent acoustic tube that could hardly be detected by people around you, this is also Perfect for surveillance purposes and security at airports, casinos, crowd control at conventions and concerts, and other working environment requiring discreet communications. This is exceptionally Perfect for usage in high environment such as driving, riding motorcycles and bicycles. Compatible with all 3.5mm enabled devices, such as cell phone, smart phone, laptop, computer, gaming. (for 4s / 5 / 5c / 5s / 6 / 6 Plus, for / mini / air 2 / 4, for Galaxy S4 / S5, Note 2 / 3 / 4, ,for , for , for Blackberry, etc. ) for use in police, , nightclubs, , , security, restaurants, hotels, bouncer, warehouses, and noisy environments. Function: for ,Monitor Headphone Support APP: No Is wireless: No Support -x: No Volume Control: Yes Style: Headphone Active Noise-Cancellation: Yes Support Memory Card: No Sensitivity: 100+/-2dB Wireless Type: None Waterproof: No Frequency Response Range: 20-20Hz Communication: Wired Vocalism Principle: Dynamic With Microphone: Yes Control Button: Yes Resistance: 32 ohm Plug Type: Type Specifications: Net Weight: about 2.2oz / 62g Compatible: All 3.5mm enabled devices Color: Black Material: ABS size: Connectors: 3.5mm Package Contents: 1 x Throat Mic earphone Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.