Bar Fly 4 Max Mount 35.0 and 31.8mmLarger mount capable of handling the Garmin 800 810 1000 Computer face mounts level with bar stem for a cleaner look Now includes mounts for all these items: Garmin, Mio, Magellan, Wahoo, Polar, Cateye, Bryton, GoPro, Di2, and lights Absolute click when computer is locked into position 35. 0 and 31. 8mm diameter handlebar clamp compatible (hardware included) TECH SPECS model 4 Max mount mount handlebar clamp size 35. 0 and 31. 8mm color black