Made from the highest quality tungsten carbon. Has airfoil shape for a clean, no-drip spray application. Features a hand-tight nut. No tools required for assembly or adjustment. Fewer parts, less complicated. No. 561-001: 11/16-16 thread, F base, for use with guns: Airlessco 007, ASM, Campbell Housfeld, some Wagner No. 561-002: 7/8-14 thread, G base, for use with guns: Airlessco 007, Graco, Titan, some Wagner