Made these for my mid-rise 6000 lb.scissor lift to give me more room to work on exhaust systems or for lifting a pick-up truck for repairs. I used 3x3x.125 box and 1/4" for all else. The height can now add and additional 9" the the lifts capacity. I added round rubber pads that I bought on e-bay for post type lifts to round 1/4" by 6" discs to add stability. I used 2x2x 1/4" angle and cut and machined it to size to make the base slides. The short one is what the lift comes with. I know these are available from the manufacturer but I had everything on hand to make them and saved myself a couple of hundred bucks. Using these on a car requires a little more set up time, but its worth it. Thanks for looking.