Firstly, the need for any screws or tool to secure the fins has been eliminated; the fins now simply lock into the plugs. Secondly, the leading edge of the fin resides inside the plug, and the base of the fins sit flush to the surface of the board creating a more seamless connection. The final key feature of the new system is that itās backward compatible, meaning it will accept fins from the original dual tab system. Adding two grub screws and a small silicon insert allows you to secure your two tab fins into the new system.