[SupremeDeluxe]

I have had a lot of lifts and I have 4 now. They are Auto Lift brand, made in China. Most importantly, they have mechanical locks and you can easily discern if they are locked or free.

I have heat in my floor so I can't anchor them, but they are on dead-level and flat floor and don't shift.

My Bendpak was on a terrible floor and I had it shimmed and anchored for stability. The air locks are a menace in my experience. You have to sight it carefully when you are lowering, because they are all independent and you can hang one and have a bad day. You also have to visually check to ensure that all four are on the slots and locked when you rest it at the raised height. Someone inexperienced can easily make a mistake. It looks like the one that crashed has air locks.