'80s GM F-car (Camaro/Firebird). Corvettes, Mustangs, and several other cars use them; my '97 Mustang GT has one. A little bigger than palm-sized. You'll need a relay, a switch, a puke tank & related hoses & wiring. Total weight maybe 8 lbs. Doesn't pull as much vacuum as the "real" pumps, but I'm in the whole deal maybe $75 including the used pump, and it works for my setup.
I measure the vacuum using a fitting on the opposite valve cover.
Crank end seals & anything that can weep needs to be sealed as tightly as is reasonable, so no pop-off breathers.