Isvidda Flex skates are equipped with holes for a variety of bindings. Their body is made of aluminum and the runner is 1.5 mm thick stainless steel. When choosing from the available lengths, remember that while shorter skates are a bit easier for beginners to control, longer ones make for better stability and efficiency. - Manufacturer recommendations for skate size in comparison to shoe size: - 36 - 39: 45 cm skates - 40 - 43: 50 cm skates - 44+: 55 cm skates Compatible with Prolink and other bindings that do not use an IFP or NIS plate. Not compatible with NIS or IFP systems. The package contains two skates.