When the fitted sheets come off the bed it absolutely drives me nuts!! I have tried so many different products to keep the fitted sheet on the bed and have had no luck with any products, but this product works! They are so easy to install. You put the L shaped piece under the mattress, then you put the fitted sheet over it, the peg goes into the opening on the clip, you will then hear a click and that will tell you that it is secure. Even if you have a heavy mattress it is still easy because it is just a matter of sliding the L piece under the mattress, you don’t have to lift the mattress to get it under it.