Stop contaminants from entering your 37-degree AN flare fittings and hose assemblies during storage, maintenance or repair. Also useful for masking during dipping, painting or plating process. Knurled for ease of installation with only light finger tightening and threaded to meet low pressure requirements without the use of o-rings. Includes four caps and four plugs in -4, -6, -8, -10, -12 and -16 sizes. A must have for any tool kit or trailer! Made In USA