Knog PWR is a 2000 lumen PWR mountain bike lamp holder. Designed to hold the light firmly on the handlebar, it's easy to mount and can be done above and below the handlebar. It allows you to quickly release the light when you park your bike. CENTRAL MOUNTING: The design favors central positioning of the light above and below the handlebar. TIGHT SCREW: Allows additional tightening COMPATIBILITY: All PWR lights For diameters: 31.8 mm and 35 mm Weight: 20 g .