Model: 500A - Maximum talking range 500 meters between two BT interphones real two-way wireless - Effective operation up to 120km/h speed - 10-meters Bluetooth sensing range - Wireless hands free communication for motorcyclists and skiers - Support Headset profile Hands-free A2DP+EDR profile - Works with any Bluetooth equipped mobile phone or MP3 for stereo music - Up to 7 hours talking time - Up to 100 hours stand by time - Auto receiving cellphone calls - Fits any motorcycle helmet - Fully weather protected - Wind and noise compensating microphone with slim headset speaker - Drive safely while talking with friend - Built-in 500mAh rechargeable battery recharged by the included AC adapter or any powered USB port - Package included: - 2 * BT interphone - 2 * Rider speakers and microphone - 2 * Helmet mount kit set - 2 * USB charging cable - 2 * 100-240v US plug AC USB adaptor - 1 * Screws set - 1 * English User manual