Another option is Herbie's Audio Lab Threaded Stud Gliders, i believe they work for racks as well.
Any racks that use coasters/ wheels ?
I know salamander does racks with coasters but are there any others?
Never understood why people don't like coasters for the racks. It's impossible to move a rack after being populated with components without major effort. Not sure the isolation value is all that meaningful, ie. Not using coasters. Unless you got a turntable