I cover every mattress in the house. This pad is the best because the vinyl inside is laminated which means it holds up but also stays silent. I have one under our padding on our kind size bed and bought this for my teen. The multi-pack is great if you have several kids and for home and college dorm beds if they have regular size twin beds. I think it's available in extra-long twin as well.
I am kicking myself for purchasing these at $** for three! They're an inch thick at the tips of the contours, more like 1/2 an inch at the valleys, so to get a really soft feel I have to use two or three. I'm also disappointed by the quality of the foam, it seems lacking in density. Definitely keep shopping!