These work like a charm!
I have a set of sheets that I love that I almost threw out the bottom sheet because I thought it was hopeless. I think that the elastic was never tight enough on the sheet or something, but it always lifted up and I really was really ready to just throw the bottom sheet away and find of solid sheet to compliment the top sheet. Then I decided to try these and they work 100%! Then I thought I was going to have to lift the whole corner of the mattress to put it on when all I had to do was just lift the corner of the sheet, put the suspenders in place and tuck it back under as you normally would. I only needed to use 2 of the 4 because only the top of the sheet had the problem. If you're on the fence about these don't be. Get them! Overall great buy and I highly recommend.