Mounted to the sides of the helmet, the unique, streamlined design of the Ops-Core Accessory Rail Connectors (ARCs) allow for the quick, easy and secure donning and doffing of headborne accessories. Designed to emergency release accessories at 8ft-lbs (11 Newton meters) of torque to prevent neck injuries in the event of snagging, all FAST and Sentry helmets come standard with Ops-Core ARCs, with replacement kits available as needed. To cost effectively add performance capability, ARC upgrade kits are available for ACH style helmets. Rail adapters are available to attach mission specific accessories to the ARCs. For NVGs, Ops-Core Shrouds provide a secure attachment at the front of the helmet.