Independent volume adjusting (driver and co-driver). External shape is designed for an easy fitting to rollcage and panel.Female Nexus military connectors. Integrated internal cable for an upgraded reliability.Powered via a 9v PP3 battery (not supplied) or 12v car battery (integrated cable). 3 noise reduction filters, 2 different amplification possibilities for a total of 6 settings. Developed for Sparco crash helmets but totally compatible with most common crash helmet on the market.Automatic switch on once the co-driver crash helmet is plugged in. ON/OFF signalling led.3,5mm connector for mobile phone (I-Phone, Black Berry, Nokia, Samsung). RCA output for on board camera.