Cardo SCALA RIDER QZ: Make & Receive calls - connect 2 mobile phones simultaneously. Receive GPS (Sat-Nav) audio instructions. Wireless stereo (A2DP) and remote operation of compatible MP3 players. Customise settings and receive software updates. Hot-dial number (Customisable). Replaceable stereo speakers (3.5 mm). Self-adjusting speaker volume according to speed and ambient noise (Customisable). Voice-control to answer mobile phone calls. Up to 10 hours talk-time / 1 week stand-by. Waterproof and Dustproof.