Water Proof H1 3/5mm no Bib Hood Waterproof Brand 3/5 mm H1 Venting Hood without Bib - XL 3-D shaped - Glideskin seal - HAVS system - I-Span superstretch nylon - Bonded Hi-Quality Nylon thread Waterproof H1 5mm includes the unique HAVS (Hood Air Venting System) which uses one-way valves to vent annoying air buildup in the hood. The H1 5mm Hood features a 5mm double layered protection in critical heat loss areas and glideskin seals for the neck and face. Bonded High Quality Nylon Thread