Description: - Replacement Diving Fins Spring Heel Straps made of 304 Stainless Steel and rubber- durable, elasticity - Suitable for most open heel fins, such as for Cress, for Mares, but Not for Gull Coco fins. - In order to ensure that it can be used, please measure the distance between the base of the fin pins (14mm or 20mm.) -Designed to keep fins and flippers from slipping off -Using quick release buckle let you easy to put on and take off your Fins Specification: Material: 304 stainless steel + POM + Product size: XS: 270x30x10mm/10.6x1.18x0.39 inch S: 295x30x10mm/11.6x1.18x0.39 inch M: 305x30x10mm/12.0x1.18x0.39 inch L: 325x30x10mm/12.8x1.18x0.39 inch Size Chart: XS: Suits Heel circumference: 25.5-29cm/10.0-11.4" For shoe size: 34-39 Inch S: Suits Heel circumference:28.5-32cm/11.2-12.6" For Shoes Size: 38-42 Inch M: Suits Heel circumference: 31-34cm/12.2-13.4" For Shoes Size: 41-44 Inch L : Suits Heel circumference: 33-38cm/13.0-15.0" For Shoes Size:43-48 Inch Package Includes: 1 Pair Diving Fin Spring Heel Strap