Automatic the plug is separated from all couplers when pulling sleeve back. Max working pressure is 300 PSI Industrial/Milton style coupler · Brass construction · Intended for use on compressed air lines only · Max working pressure is 300 PSI Pls make sure you do not mind before you bid3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Industrial/Milton style coupler , Brass construction Milton High Flow Air Fittings Industrial/Milton Style Push Coupler, 1/4 In X 1/4 In MNPT Air Tool Fittings Easy Operation Four locking balls in the coupler Hich hold the plug securely, insert plug into coupler when pulling sleeve back. Forney 75600 Air Fitting Plug, Industrial ilton, 1/4-Inch by 1/4-Inch... Intended for use on compressed air lines only Milton S790 Lincoln Style Air Hose Coupler Female 1/4 In NPT MILS790 For more information go to www.P65Warnings.ca.gov Max working pressure o300 psi.