Every HVAC Pro needs this bit in their multi-bit screwdriver. I keep two or three of these spare Klein Tools 32528 Schrader valve core tips in my collection in case I lose one like the rest of us. I use them in two different screwdrivers I have, but the one I use the most is the Klein Tools 32593 6-in-1 Stubby Ratcheting Screwdriver. I replaced one of the bits that came with the screwdriver and use Stubby to remove the HVAC blocking caps which are almost always in tight spots. Stubby is perfect