Used Mares Avanti Pure FinsAvanti Pure Diving Fins The Avanti Pure diving fins feature a blade length that varies between 27 and 34. 5 cm, depending on the size. These fins are designed with an open foot pocket and are constructed using bi material. The foot pocket is soft and comfortable, allowing for barefoot use or with soft socks. Additionally, the fins are equipped with guides to secure the elastic bands and prevent foot pocket rotation.