Mares Razor Food PocketRazor liners are designed for 3mm neoprene boots. If you prefer to wear these fins barefoot, we recommend that you choose the next smaller size. The Razor fin foot pockets are the original spare parts for your freediving fins. The package contains 1 foot pocket. The key features of the Razor fin foot pockets are: Liner designed to be worn with a soft 3mm fit If used barefoot, choose one size smaller Compatible with blades: Razor Matrix (420911) Razor