Ronix 2.5" - Fin-S 2.0 Tool-Less- Center Surf Fin-Blk (2018) Description Ronix's 2018 Surf Lineup features Fin-S 2.0, the most advanced wakesurf fins ever made. A thinner profile creates less drag with the water, creating more top-end speed and acceleration. The outside fins now have an asymmetrical shape and cupped inside foil that create noticeably more speed and drive once a turn is initiated. Ranging in size from 2.5" to 4.5" you can now completely change how your board rides by easily changing the fins in a matter of seconds. Dialing in your board has never been this easy. Welcome to the future of wakesurfing.