Robinair's No. 40352 premium quality replacement valve cores are designed for use in air conditioning systems. Compatible with both 'low' and 'high' pressure refrigerants - R-12, R-134a, R-22, R-410a and more. With the high cost of refrigerant it makes sense to use high quality Robinair replacement valve cores when servicing air conditioning systems. Pack of 6. Robinair, a Bosch Automotive Service Solutions brand, is a global leader in service tools and equipment based in Owatonna, Minnesota. Robinair is recognized throughout the world as the quality and performance leader in AC/R evacuation tools and this position has led to its success with the full range of products that serve the heating/ventilating/air conditioning/refrigeration (HVAC-R) and mobile markets.