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 for this and always handy in my top pocket.