Valve Core Remover Installer Exchange Extractor with Air Contitioning Schrader Valve Core Replacement AC HVAC/R Field Service Tool Improved Model Valve core remover installer work on charged systems Replace damaged leaking valve core without loosing the charge in air condition systems Solid design and construction, high quality service tools for decade to come easy connect with 1/4 or 5/16 R22 or R410a systems yes, dual size for professionals and do-it-your-self handy men alike