Induction neckloop with 30dB adjustable amplification. Compatible with standard Bluetooth version 1.2/2.1 devices such as mobile phones, cordless phones, computers, MP3 players, and any radio device using the standard Bluetooth transmission. Has user friendly controls for easy pairing, one-touch answering button and compatible with voice dialing (if supported by your cell phone provider). Neckloop can be adjusted with the push-button slider for optimum microphone placement. Quick release feature on the neckloop for safety and convenience. Powered by a lithium ion rechargeable battery. AC adapter, USB cable and car charger options are included. One year warranty.