Spring heel fin straps are popular because they are extremely reliable and easy to use. Because there is nothing to clip, snap or adjust, spring straps make putting on and removing your fins easy and fast; especially if you have to do it in the water! They automatically adjust to the divers feet during the dive, compensating for depth and compression of boot material. The Mares XR Spring Straps are made from stainless steel springs and covered with nylon tube webbing to protect the spring and provide padding. Nylon line on the inside of the spring prevents over-extension of the strap. The "large post" adapter works for almost all modern fins that have a standard molded post attachment point (including Mares brand fins) but will not work for Atomic or "old school" rubber fins.

The straps are available in three different lengths: Regular { 12 in | 30.5 cm }, X-Large { 13.25 in | 33.7 cm }, and XX-Large { 14.5 in | 36.8 cm }. Length refers only to the center hole to center hole, not overall length. Sizing is not critical because springs of course do stretch to fit, so choose the length based on the size of your fin and your preference for a snug or loose fit.