Rack version solves the problem that using racks can often obscure the rider's rear lights, instead mounting on the back of the rack. Includes 2 brackets to fit 50mm and 80mm spacing Saddle version mounts just below the saddle, keeping your seat post clear of clutter and placing your rear light at the best position for maximum visibility. Chip on Board (COB) LEDs provide maximum brightness level for up to 90% of the battery burn time Clip design allows a rider to quickly remove or attach the light to or from the mount 8 eye catching modes 100% waterproof with IP67 rating Bright & punchy 100 lumen output Be seen from over 3000 ft USBC rechargeable (cable not included) Up to 50 hr runtime Low battery & charge indicator