O’Neill’s innovative patented Z.E.N. Zip Entry system is the most imitated entry/closure system in the world. This free floating exterior mini zip allows for a zipperless feel and stops water from entering the wetsuit. (U.S. Patent #5,898,934). Pullover internal seal that blocks out water for maximum performance. Water that penetrates the Z.E.N. Collar or Super short zip is blocked by the Barrier-2 and forced out the drain hole.