Hammerhead Karoo Mounting System Description: The Hammerhead Karoo Mounting System was designed from scratch by Hammerhead to be stronger, lighter and lower-profile than other mounting solutions on the market. Features: Fits on 31.8mm handlebars Stronger, lighter, and lower-profile than other mounts on the market Specifications: Device Compatibility: Karoo Handlebar Diameter Compatibility: 31.8mm Weight: 36g