The Helicopter Crew Vest is a 35 pound buoyancy vest encapsulated in a cover of 420 denier weave nylon. Designed for constant wear this vest is the standard of the industry. This vest meets FAA/TSO C13d and UK CAA/ARO 1349. The HV-35C comes standard with a water activated light and two 18 gram CO2 cylinders and is fully adjustable for waist/chest sizes up to 50".