316 Stainless Steel Alloy Flush Mount Fuel Vent - Straight Vent On the exterior, they have a smooth edge over the competition. Unlike some others, there is no protruding cap to cause damage or be damaged by hull bumps and scrapes. Cap unscrews with a hex head wrench for easy cleaning of the filter and pressure testing of the entire fuel system. These vents now include two silicone gaskets.Features:Straight VentSpecifications: Hose Size (inch): 5/8" inner diameter Maximum Hull Thickness (inch): 7/8" Installation Hole Size (inch): 1-3/8" *Includes two silicone gaskets Quick Guide (pdf)