D‑Fender protects your back and backside from water and mud spray coming off the rear wheel. A mudguard designed to bolt onto the head of the BMC D-shaped DS5 seatpost (27.6 × 27.2 mm), using the threaded insert co-molded into the seatpost head. It is compatible with both 0 mm and 15 mm offset DS5 seatposts specified for the Roadmachine Gen 2 & Gen 3, URS Gen 1 & Gen 2, Twostroke Gen 1 & Gen 2, and Kaius Gen 1.