Very durable and sturdy. They are adjustable and inexpensive. I love how adjustable they are, and how secure.

Reviewer says clamp * ripped their sheets. Heavy mattresses make it difficult to tighten. Dvd player has no instructions. Not suitable for metal bed frame or heavy mattress.

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.