Designed to fit the Ops-Core FAST Ballistic and Maritime Helmets Stretch fit Allows access to night vision mounts and rail accessories Loop for attachment of IFF capabilities Individually sized and 100% fit tested the FirstSpear Hybrid Helmet Cover is designed to fit either the Ops-Core FAST Ballistic Helmet or the Ops-Core FAST Maritime Helmet. A stretch fit ensures that it remains in place during free fall or rotary wing operations and key areas of the cover have been manufactured to allow access to night vision mounts and rail accessories. Loop is positioned in other locations for attachment of IFF capabilities. Perfect for changing your helmet s pattern, preserving its finish and dampening noise during impact. Your read more about the Hybrid Helmet Cover at Soldier Systems. Helmet Sizing Small/Medium = Medium Medium/Large = Large Large/XL = XL