Unique Design: Depth 9 inch, base 5.5 inch. Designed for a balance of speed, flow and response, suitable for all wave conditions. It's a preferred choice for beginners and expert surfers. The design of curve radian make it maneuverable for you to paddle on the SUP board and better control of direction and speed. This fin fits standard US fin box. Be sure to measure and check the size before purchasing. Lightweight and Stiff: Made of high-strength fiberglass with honeycomb. The fiberglass conostruction make the fin stiff and flexible. Designed for a balance of speed, flow and response, suitable for all wave conditions. Protective: Come with a soft protective neoprene cover. Protect the fin from dirt, dings and scratches, easy for storage and carrying. Easy to Install: With the cross screw, it is easy to insert and remove the fins, you can install the fin on your surf board only in a few seconds. Abahub Warranty: we've been manufacturing fins for over 10 years. We know what we're doing and we stand by our products. If you're not happy with our products, we'll offer you replacement or refund with "No Question Asked" warranty. Abahub 9'' SUP Single Center Fin with 1 Cross Screw, Fiberglass with Honeycomb 9 inch SUP Replacement Fins for Surfboard, Stand-up Paddle Board, Longboard, Blue