DIR style .025 stainless springs feature heavy-duty nylon tube webbing and internal line to limit overstretching of springs. One kit attaches to almost any scuba fin. Three styles of 316 stainless steel buckles included: Old School buckles fit Turtle, Power, Frog fins; Large Post buckles fit most of today's modern fins; and Small Post buckles fit Atomic split fins. Available in 8, 10 and 12 lengths.