Riffe’s Composite Fiberglass Fin Blade Set (sold in set of 2) RIFFE has partnered with renowned top of the line fin blade manufacturer DiveR. Custom epoxy resin system and aerospace grade fabrics produce a fin that transfers load progressively from toe to heel. Fiberglass are produced with a “medium” hardness for optimum performance. Warranty invalid if damage caused by misuse (jumping off boat with direct water impact, hitting propeller with fins, walking on rocks). Walking backwards towards ocean is recommended.