The Ox - Full Face Oxygen Skydiving Helmet Helmet Bag:Cordura Helmet Bag (+$36) Collar adjustments are made by

Collar adjustments are made by simply pulling slack in the cord and re-knotting

Medium - 22

quality helmets are designed and manufactured by us in the USA out of carbon fiber - not the plastic most skydiving helmet manufacturers are currently using

For the largest shell  (#3) the chin was brought out just a smidge with the same width of the Aero that fits the more  bulbous heads

The Ox - Full Face Oxygen Skydiving Helmet Helmet Bag:Cordura Helmet Bag (+$36) Collar adjustments are made byThe Ox Full Face Oxygen Helmet was developed by Bonehead Composites specifically for HALO HAHO jumpers using oxygen systems. This purpose built helmet was developed with consultation from jumpmasters for Project Cirrus for their four world record attempts: Highest Altitude Jumped in a Wingsuit Longest Time Flown in a Wingsuit Highest Speed Flown in a Wingsuit World Speed Record of 249mph completed on 6 1 2017 Farthest Distance Flown in a Wingsuit