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