The Lezyne Femto Drive Rear complements its Front counterpart perfectly, delivering excellent visibility with a 7 lm output from its single red LED. It features an integrated lens switch made of high-grade optical material, which serves as an activation button that cycles through four Flash modes & one Solid mode. The CNC –machined aluminum body is lightweight, durable, & extremely weather-resistant. The Composite Matrix back cap features the Clip-On System for versatile strapped or clipped mounting. The multi-position silicon rubber strap attaches directly to the back plate to secure the light to a wide range of seat post diameters. The Side Visibility lens extends beyond the body providing 180 degrees visibility, & increasing user safety. The back cap can easily be unscrewed to replace the two CR2032 disposable batteries. The Femto Drive Rear is available as a single rear LED, or as a front/rear pair (Femto Drive Front & Rear). Replacement CR2032 batteries are also available.