Mount your Cygolite Hotshot Tail Light to your rear rack instead of to your seatpost with this bracket.
Fits racks with one centered mounting hole, or with two holes spaced 50mm apart.
Planet Bike Tail Light Clip
Busch & Müller Tail Light Bracket T For Rear Rack With No Hole
CygoLite 3ft Extension Cord for Li-Ion Batteries