My fitted sheets fit snugly on my bed and this tool poked holes in the sheet. Ripped my sheets and was hard to use.

They do work just haven't figured out best configuration yet.

Clip keeps sheets on the bed in spite of the determined attempts of children to squirm their sheets off. Strong and hold the fabric covers in place - no slipping or popping off.

This is poorly made junk. The clips are not strong enough for couch covers. Don't waste the effort.