Used on kidd class ddg; ticonderoga class cg (47); virginia class cgn (41); forrestal class cv; spruance class dd (963); oliver perry class ffg; heater duct-type, multi-fuel, 120,000 btu/hr, skid mounted; nimitz class cvn; austin ship class lpd-4 amphibious transport docks; wasp class lhd. 1.562" overall length weapon system essential nickel surface treated straight shape, solid internal threaded coupling