The light mounts to the rear of the helmet via a velcro strap system and is compatible with almost every helmet type.Features: Weight: 21g Brightness: 40 lumen Battery Type: Rechargeable li-poly battery Solid mode run time: 3h30 Blinking mode run time: 8h30 Pulse mode run time: 14 hours Battery charging time: 2h30 Battery charging port: Magnetic charging cable