Mount your radar tail light or bike tail light (both sold separately) to a D-shaped, aero or round seat post with this quarter-turn mount. Includes mount, 3 fitting shims and 2 O-rings. Compatible with round seat posts from 25.4 mm to 35.0 mm in diameter; Aero and D-shaped seat post compatibility varies by bike model.

Works for both Varia RTL515 and RVR315 models