Brand N/A Quantity 1 piece(s) Material ABS Color Black Type Electronic Device Function Allows up to 6 riders to connect to each other at the same time (only two sets included need to buy more to connect each other). Bluetooth headset can connect to cellphone speaker audio speaker with Bluetooth function. Bluetooth Version 3.0 Transmission Range 10 m Intercom Function Yes Intercom Effective Distance 1000m Power Supply 500mA Working Current 3mA Other Features Maximum intercom distance 1000 meters (barrier-free environment no interference); Above 120km working speed; Automatic safephone calls (A2DP & EDR bluetooth; Stereo music/audio functions (use A2DP transfer cell phone/MP3 / GPS) ; DPS noise elimination function; 7 hours continuous phone call. Packing List 2 x Bluetooth interphone 2 x US plug power adapter (100~240V) 2 x Headphone 2 x USB cables 2 x Fastening accessories. 4 x Screws 1 x English manual