I bought these to replace the Discasal 2" stem casters I bought for a CNC table that wasn't working properly. They're much stronger and I can maneuver the table if they don't come with instructions on how far from the base to install them, but I've found comments online that have been very helpful. 2 inches down to get desired lift. I chose 1.75 inches for a 1/4 inch rise. If you want to make everything you build adjustable, they don't have that feature, but I've seen you can buy adjustable mounts as well.