Spring length only: Small - 7." ; Medium - 8" ; Large - 9.5". Center of the buckle to buckle length: Small: 11", Medium: 12", Large: 13".
Place the middle of the pin on the opposite end of the fin. Choose a spring strap length that is 0.5" to 1.5" (1.3 to 3.8 cm) smaller than your measurement.
Fins must have a 3/4" notch with U cutout for the unit to work
Insert your dive boot into your fin pocket, measure the distance from the center of one strap mount pin on the side of the fin, around your boot heel
Fits most fins, including Scubapro Twin Jet Max, Aqua Lung Rocket, Sherwood Triton, Tusa Imprex/Liberator/X-Pert Zoom/Solla and more.