GROCO NPS NPT Combo Stainless Steel Thru-Hull Fitting w/Nut 1". The reusable Flow-Tel Thru-Hull Nut and NPSM / NPT combination thread make the Groco Thru-Hull Coupling Fittings a necessary item for nearly any boat. These Thru-Hull Fittings make it simple to add a hose to any boat. The fittings eliminate the need for cleaning and maintaining separate hoses. They can be installed and removed with hand tools an electric drill or an alternative method of installation. The NPSM (National Petroleum Storage and Transportation Act) thread on this Groco Thru-Hull Fitting w/Nut is constructed of corrosion-resistant #316 stainless steel. Stainless steel models with nuts and lugs are the only type of fittings GROCO sells. Specifications for GROCO 1" NPS NPT Combo Stainless Steel Thru-Hull Fitting w/Nut: Manufacturer: GROCO Color: Silver Features of GROCO 1" NPS NPT Combo Stainless Steel Thru-Hull Fitting w/Nut NPSM / NPT combination thread #316 Stainless Steel Sizes from 1/2" to 3" UL Listed 647B BSPP and Stainless Steel models available Package Contents: GROCO 1" NPS NPT Combo Stainless Steel Thru-Hull Fitting w/Nut GROCO TH-1000-WS: NPS NPT Combo Stainless Steel Thru-Hull Fitting w/Nut 1"