Usage Tips:[Wide Compatibility]This seat post quarter turn mount compatible with for Varia Rearview Bike Radar, for Varia RTL510, for Varia RTL515, for Varia RVR315. It is widely used in road bikes with 27.2mm, 30.9mm and 31.6mm bars, help to keep your for Varia radar or tail light on your bicycle no matter the terrain.[More Versatile]Compatible with for Variant Rearview Radar, for Variant Smart Bike Lights.[ Construction] It is strong enough to keep your for Varia radar or tail light on your bicycle no matter the terrain.[Safe & Secure]We are confident that upgrading to a for Varia seat post Mount give you piece of mind knowing you've chosen the to securely lock and perfectly position your for Varia radar or tail light on your bike so you can focus on your goals, whether that be having fun or going fast, or bothColor: BlackMaterial: plasticPackage Contents:1 x Bicycle Seat Mount Bracket3 x GasketOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.