Valve core bit driver set ideal for use during the maintenance and repair of vehicle air conditioning (AC) systems. Designed to easily remove standard R12, PSA and Volvo M10 and R13 valve cores during refrigerant replacement, when using leak detection dye or when replacing one of the system components. The kit includes 4 valve core bits together with a magnetic holder that features a knurled grip which allows for tight valve cores to be removed with ease.