They ARE heavy, and HUGE!. But, my tire changer (Hunter TC3500) likes a lot of air, like 12.4cfm@135psi according to the manual. Milton's site says most 1/4" fittings will handle approximately 40scfm, 3/8" fittings will do 60scfm, and 1/2" fittings exceed 60scfm. Interestingly enough, it also...