Received and installed. Easy install, 2 ratchets, an awl (for stick nut alignment), one end wrench, a floor jack, and a cordless drill. Took me less than 2 hours in the driveway including un-crating and clean-up. I ordered them without the steps and weighed them before the install, 58.5# each plus the hardware. Concerning use as air tanks. I had our welding shop foreman (steam and pressure vessel certified) look at them and he advised only using the square tubing as air buffer tanks and put a 100 psi relief valve on the system, I'll update if I do this at a later date.