Comparison : Item # H480SSN1/81/3PSI, H400 Series, SS Check Valve, 1/8” Male NPT Thread x 1/8” Male NPT Thread
Item # H480SSN1/41/3PSI, H400 Series, SS Check Valve, 1/4” Male NPT Thread x 1/4” Male NPT Thread
Item # H480SSN3/81/3PSI, H400 Series, SS Check Valve, 3/8” Male NPT Thread x 3/8” Male NPT Thread
Item # H480SSN1/21/3PSI, H400 Series, SS Check Valve, 1/2” Male NPT Thread x 1/2” Male NPT Thread
Item # H480SSR1/8, H400 Series, SS Check Valve, 1/8” Male BSPT Thread x 1/8” Male BSPT Thread