Lightweight and ultra slim design for nearly any size helmet. Bluetooth® specification v4.1. Bluetooth Intercom up to 900 meters (980 yards) in open terrain. Four-way conference intercom. Also uses the Universal Intercom™ to communicate with all Sena and non-Sena Bluetooth® headsets on the market. Voice Prompts. Bluetooth stereo headset by A2DP. Bluetooth music playback control by AVRCP: play, pause, track forward and track back. Sufficient sound level with integrated audio booster. Bluetooth hands-free for Bluetooth mobile phones. Bluetooth headset or stereo headset for Bluetooth GPS navigation. Water-resistant for use in inclement weather. Advanced Noise Control™. Music sharing allows talk or share playlists with the four-way intercom function. Up to 10 hours talk time, seven days stand-by time. Can be used while charging on road trips. Individual volume control for each audio source. Firmware upgradeable. 10S Smartphone app makes configuration a snap – change settings, set groups of intercom friends and access a Quick Guide; pair up to two mobile phones for convenient hands-free calling. 2- Speakers. 2- Foam speaker covers. 4- Speaker pads. 1- Wired boom microphone. 1- Wired microphone.