The Asteroid fits all new and older Bern helmets with a two-hole mount located in the rear of the shell. USB rechargeable. - 12 Lumens - Micro USB rechargeable - 3 Light Modes (Flash 24 hours, Pulse 6.5 hours, Steady 5.5 hours) - Water Resistant - 16 grams - 26mm tall, 39mm wide, 20mm thick (w/o bracket)