The S-1 Pro is Severne's ultimate 4 batten wave crushing machine! The Pro model of the S-1 is the extreme light weight membrane version of the legendary S-1. This sail favors back handed riding that goes hand in hand with your multiline wave board. If you're looking for a locked in feel or using a single fin board, the Blade Pro would make a better choice. If you want to rip your quad harder than ever through a bottom turn and throw enough spray off the top to blind the guy on the wave behind you, the S-1 Pro will do the trick.