This is the IST S19 5mm Nylon II Tall Cut Scuba Diving Boots with Molded Sole and Heel Cap Features: 5mm nylon II boots Vulcanized rubber sole with Additional Heel cap for protection and durability Built-in fin strap keeper No.10 ultra durable zip Height: 20cm (8) These 5mm boots feature a flexible molded sole designed to provide unparalleled comfort on sandy beaches and boat decks as well.