Authentic Schrader Valve Core Remover/Installer Tool with automatic click for proper torque. These valve core tools are brand new and made by Schrader International Inc. When valve core is torqued to the correct ft/lbs, the handle clicks and stops turning the valve core, thus insuring the correct torque measurement and prevents overtightening. For use in air conditioning and refrigeration. Will also work on automotive/truck tires, R12 automotive AC systems and bicycle tires.