The Lezyne Femto Drive Duo is a two-in-one safety light integrated into a versatile helmet mount. Front and rear light coupled by a composite matrix junction. Compatible with nearly all vented-style helmets. LEDs are housed in a super compact, lightweight and durable machined aluminum body. High-grade polycarbonate lenses provide side visibility and double as the power button. Front: 15 lumens, Rear: 7 lumens, two output modes. Easy to replace CR2032 batteries.