popular home goods store, and on the back of the package, it just says to ,“lift top plastic piece to open fastener.” At first, I did not see how to do that. Then I figured out that you pinch the part where the latch attaches to the elastic with one hand and press the latch downward with the other hand. That loosens the latch and allows you to pull open the jaws of it. Insert the edge of the sheet, snap the latch back together and back into alignment with the elastic. However, the elastic is too short to help much with our beds because the sheets pull off further from the corners. It’s hard to attach one in such a position in advance of putting the sheet on the mattress, so it’s awkward getting down to the bottom of the mattress to attach it. Plus, this will only work if I add more elastic. Also, with very little pressure, the closed latch will quickly pull off of the sheet.