This trundle bed was purchased, after much market browsing, to replace a sofa bed which was no longer required for visiting parents. Time moves on. What was needed was something for visiting grandchildren. This was the perfect solution, easy to assemble, excellent quality and exactly what was needed. For all those folk who, like us, found the website ambiguous, be clear that: the lower bed rolls out on 3 pairs of casters and is in no way connected to the main bed, so is completely separate. It cannot be raised to link in as a double bed. We needed this to double up as a sofa and purchased the bed without mattresses which we were happy about because, with the recommend 25cm thick mattress, my feet wouldn’t touch the floor when sitting on it (and I’m 6’ 3”). It works fine with a 3rd party 12cm thick foam mattress (IKEA, if I’m allowed to say that) and is really comfy for both sitting and sleeping on. Shame that the black lower upholstery shows with the thinner mattress, but it’s covered with cushions, so no biggie. The thinner mattress also allows more bedding to be stored underneath along with the lower bed.