Compatible with Single Tab fin box Materials: fiberglass.Quad fins future uses ultra-durable fiberglass。These quad fins are LIGHTWEIGHT, RESPONSIVE, and FAST. Quad Fins increase surf speed in small waves, and two front fins enhance the stability of the board. Suitable for most wave conditions. Rear Fins Base:4.37 inch；Height:3.62 inch. Front Fin Base:4.37 inch；Height:5.43 inch.The fin section is a traditional single-sided flat design, helping surfers to freely enjoy speed and passion on the waves. DURABILITY: Tested and thrashed by UPSURF professional group to make sure what buyers ordered are durable enough for usage. We are a surf company been in Surf industry more than 10years in China.We worked for some big brand many years.We have our own designer team for surf products. We have our own designer team and production team for surf products.There is some new brand for online shop are on the way .We are have very profession and responsibility sale steam.Our major is to supply the high quality and good price products for our customer. If you are a shop or you are a surfer,and interesting to distributor our products,please don't hesitate to contact with us.We will find out the best way to serve the surf products market.