Seac Propulsion Sling Strap FinsPropulsion Sling Strap Fins The fins Seac Sub Propulsion S, very high performance, virtually indestructible, created in technological material EVA , impact and stress resistant, tough at low temperatures, unassailable by fungus or bacteria, anallergic and non toxic, UV resistant. he. The EVA provides at the same time great softness and flexibility. Designed for challenging dives at more rigid temperatures but well suited to any kind dives and level of