Beaver Easy Fin Spring Straps Quick Release Pair of spring straps, designed for fitting & use of fins. Features: Easy, no strap adjustments are necessary once installed Simple to remove and easily changed from standard fin straps to suit most popular fin models Manufactured from rust resistant marine grade stainless steel Sizing: The strap laid flat the distance between the centre points of the holes for the attachment lugs is as follows: Small 27cm / 10.63in Medium 29cm / 11.41in Large 31cm / 12.20in XL 34cm / 13.38