The baby has a tendency to pull her sheets off her mattress in her crib, so I thought maybe we could use these sheet fasteners to help her keep them on. They have plenty of stretch and pull to allow you to attach them and keep things in place. But the fasteners themselves are not as good as I prefer. The others I have on our beds are metal, but these use plastic attachment ends. They work the same way though. I just worry the plastic may snap if she pulls too hard on the sheets. But they are serving their purpose and are easy to use. So far she hasn't pulled the sheets off again and the corners are all staying wrapped around the mattress the way they are supposed to.
Get yours here: https://amzn.to/2Q3i5fj