This is the IST Stainless Steel Spring Straps Pair with Quick Release Buckles Features: FS-10 Spring fin strap with complete IST FB7 buckles Rust resistant stainless steel spring straps Ideal for technical and recreational diving The main advantage of these straps is that when fitted, fins become easier to put on and take off (approximate spring length) - S: 17.1cm(6 3/4) - M: 19cm(7 1/2") - L: 21cm(8 1/4") - XL: 22.8cm(9") Dive in style and comfort with ease of use! "