One kit attaches to almost any scuba fin DIR style .025 stainless springs Internal caveline to limit overstretching of springs Heavy-duty nylon tube webbing 3 styles of 316 stainless steel buckles included "Old School" buckles fit Turtle, Power, Frog, Jet, Twin Jet, Rocket and others "Large Post" buckles fit most of today's modern fins "Small Post" buckles fit Atomic split fins sizes 8", 10" & 12" Available