The sheet holder straps are roughly 12” across and need to be centered under the mattress. I have no clue how someone with a bigger bed could attach them without having help.

I highly recommend them. It saves a lot of time each day on making up the beds, especially if any of them are against a wall and not accessible from all sides.

Did not get what was pictured in the item description. Each arm of the straps only has a single clip on the end. Trying to get this underneath the mattress and to stay put while moving the mattress back was next to impossible.