Fitting socket screw plug and gasket for G 1/4 BSPP Koolance threaded connections. Made from brass. Koolance's product warranty does not cover the use of 3rd-party coolants, coolant additives, or corrosion. Koolance LIQ-702 or LIQ-705 coolants are strongly recommended to help avoid issues with mixed metals or biological growth. Additionally, do not use aluminum with bare (unplated) copper or bare (unplated) brass in the same system. Do not use silver with nickel in the same system.