Bar Fly 4 TT Mount 22.2mm Clamp Diameter (Fits Most TT Bars)Compatible with Garmin Edge 200 500 510 800 810 1000 and Touring Touring Plus models and other computers 1 8th turn mounting system so your computer watch screen is always at proper orientation to rider when mounted to TT Tri bars 22. 2mm clamp diameter (fits all major TT extensions) Mounting positions on inside and outside of aero extensions Compatible with hydration systems and center bottle mounts Now includes mounts for all these items: Garmin,