Helps holding the fin in place during diving. Available in medium and large.
Fin Retainers are superb accessories if you need to ensure your fins stay securely in place. They are a popular addition to full foot fins.

While these come in pairs and are in two sizes - Medium and Large, please note that sizing is approximate and depends on what type or size of fin they will be used over. Being rubber they allow for a secure fit.

Ankle sits through two straps while the third holds the fin in place from underneath.