Topeak D-Flash Express ST Clip-On Fender – Rear Fits Seat Tube Black. Topeak D-Flash Fenders- Durable polypropylene fenders are ultralight stylish quickly attach and ready to go when wet weather arrives – no assembly of the fender required. Simply remove from the packaging and fold along the perforated line to mount with hook and loop straps which provide fenders to fit a wide range of bikes and keep you and your bike cleaner.