Authentic Schrader International Standard AC Valve Cores 1/4" - Neoprene seal. 800 PSI operating pressure. -20 to 220F operating temperature. Will fit most ac's, freezers, coolers, ect. Will fit most R12 ac systems including autos.  Will also fit most automotive/truck/bicycle/ect. tires with a standard valve core. Made in the USA by Schrader International.