Koolance patented quick disconnect no-spill coupling with automatic shutoff. 13mm (1/2in) ID male straight connection with compression fitting. It will only fit a Koolance QD3 female quick disconnect. After pulling the ring on the female QDC side, the quick-disconnect fittings will separate. Liquid on both sides will be automatically obstructed with approximately 0.2ml freed. Coolant volume lost upon disconnection will rise with internal pressure higher than 0.5kgf/cm2 (7psi). 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.