My Kobalt compressor pump took a ****, so I was on the hunt for a new pump. Found the HF pump, good reviews and it puts out 15.2cfm@90psi. Picked it up and this thing is YUGE! V twin Harley, lol!! Anyway, got it mounted and figured out I needed a 4.36 diameter electric motor pulley to be where the pumps making the cfm. So I found a 4.25, puts me 50rpm shy of 1050 for the pump. Plus it’s dual pulley to match the HF pump pulley. Almost done getting it together.