uxcell Rubber Watch Strap Retaining Keeper Hoop Loop Buckle Holder Ring 5pcs Multicolor Designed specially for fitbit Alta/Flex to protect the clasp loose and band fall off This simple insurance will keep your Fitbit safe. Light weight and more flexible Size: 20 x 7 x 8mm/0.79" x 0.28" x 0.31"(L*W*T) Fit Strap Width: 17mm/0.67"