Fit Cuffs – Performance Upper V3 includes a pair of the brand new (Arm Cuffs V3) that has the same width as the original Arm Cuff, but engineered for even faster attachment. This is state-of-the-art exclusively developed for Blood Flow Restriction (BFR) Training. Fit Cuffs works by inflating solid yet pliable cuffs by means of a solid pressure gauge and a solid metal quick-disconnector. It will fit about all arm sizes (2 x Arm Cuffs 20-50 cm / 7.9-20 Inch). One-Size-Fits-All.