The Lezyne Femto Drive Duo is a bit of a "best of both worlds" sort of light, incorporating both front & rear lights. The Femto Duo is a two-in-one safety light integrated into a versatile helmet mount. Evolved from the popular Femto series, the unit features a front & rear light coupled by a composite matrix junction that’s compatible with nearly all vented-style helmets. The LEDs are housed in a super compact, lightweight & durable machined aluminum body, & the high-grade polycarbonate lenses provide side visibility & double as the power button. The front emits 15 lumens, while the rear puts out 7 lumens; both feature three different output modes. With easy to replace CR2032 batteries, the Femto Duo is a simple front & rear lighting system for increased nighttime visibility.