C14 E-Bike TaillightE Bike Tail Light $85. 00 $100. 00 The exceptionally powerful 45 lumen rear light is fully integrated into the saddle clamp. Please measure your seatpost to determine the appropriate size. Sizing listed is representative of the approximate outside diameter of the seat tube for which the tail light will fit. Ample wire leads from the light are ready for Shimanos screw terminals. Dedicated plugs are required for two Brose drives, and the Bosch input.