After many  years of trying to find the perfect waterproof mattress protector, I have given up the search and replaced all of the others with ones from Casper.  They fit the mattresses very well and do their job.  My only issue is that, due to my constant tossing and turning, after a few days, they seem to slide off of one side of the mattress which is against the wall.  I have to pull the bed out and yank everything back where it belongs.  This is not the fault of the sheet and protector, it's my sleep gymnastics!  Great product though!