These should not be called risers as they are the same height as the standard casters on a metal bed frame and do not elevate the bed at all. Note: They are only called risers on the Wafair.ca website. On the box they come in they are called Bedframe glides. Also they do not attach to a standard metal bed frame. I'd like to return them, but unfortunately, I missed the return window as I did not try them out until after I moved from my house to a condo. Missed the return window by 7 days.