Fit Cuffs – Complete Hard Case. This is an exclusive hard case with a zipper. Fit Cuffs is a state-of-the-art Training System exclusively developed for Blood Flow Restriction (BFR) Exercise. Fit Cuffs works by inflating solid yet pliable cuffs by means of a solid pump/pressure gauge and a solid metal quick-disconnector. (2 x Leg Cuffs 45-84 cm / 17.7-33 Inch + 2 x Arm Cuffs 20-46 cm / 7.9-18.1 Inch). One-Size-Fits-All.