The Lezyne Femto Drive is compact, lightweight and safe. The lens is made of high quality optical material and serves as an activation button for the different lighting options. The CNC-machined aluminum housing makes the Femto Drive durable and weather-resistant. You can unscrew the Matrix back plate to replace the two CR2032 batteries. The multi-position silicone rubber band ensures that it fits a wide range of handlebar and saddle suspension diameters.