Navy Stock Number NSN: 4220-01-392-0301 Designed for use with the Navy MK-20 rebreather Adjustable length chest strap Split jock included 2″ nylon webbing – made in the USA 18-8 stainless steel rivet construction Two 2″ 304 grade stainless steel D-rings at waist Two 2″ 304 grade stainless steel D-rings at closure One 2″ stainless steel lifting D-ring Adjustable length shoulders straps with two stainless steel adjusters One size fits most Contact us today for information about new Commercial Diving Equipment, Used Commercial Diving Equipment and/or Kirby Morgan Helmets!