I was pleasantly surprised to receive two pads in one pack. We’re using ours on twin XL mattresses and have found them to be sizable enough to reach all the way across them. One side feels like terry cloth while the other is fairly slippery but most definitely waterproof. Fortunately there’s enough layers separating the two so you don’t get that “cold, sweaty feeling” that cheap vinyl covers cause. I subtracted one star simply because these will slide around or bunch up a bit if you move often during the night or if you tend to slide out of bed when standing up. While they certainly won’t leak, I wouldn’t call the backing nonslip.