King Cage products are made in Durango, Colorado U.S.A. These work for great attaching water bottle cages to areas on your bike that don't already have support holes! We don't recommend using them to attach a rack to your bike. 5 sizes, all sold individually: 28mm (1 1/8") for smaller tube applications 34mm (1 3/8") for steel frames and forks 40mm (1 5/8") for 32mm stanchion suspension forks, etc. 50mm (2") for aluminium tube bikes, 36mm stanchion suspension forks, etc. 56mm (2 1/4") for bikes with larger tubes SpecificationsAll USB's are 8mm wide, with metric M5 x 0.8 bolts During installation we suggest using electrical tape or cloth rim strip to protect the frame or fork legs. Rubber inner tube will lead to clamp breakage. Tighten clamp after use.