Slept on a watered for forty years, my rv mattress just didn't work after two years. I called several suppliers and manufacturers. All offered were foam mattress . I saw an ad for Engineered Sleep and watched their YouTube videos. I was surprised that they had a coil spring mattress that was rolled up into a box. I decided to call, spoke with a wonderful sales person. My mattress was 55x79 with a bottom cut corner.. Custom order, I was very impressed when it arrived a week later. Moved it into my trailer. Warning...get the mattress in place before you cut off the plastic off. This mattress expands immediately, unlike a foam mattress. Mattress weights 68 lbs and is 8 inches thick. Mattress for fit like a glove. I sleep so much better now and wake up less. I would order from them again, thanks