Initially I had a hard time putting the first slab in but after sleeping on that while waiting for the other to arrive, the knit ticking stretched out enough and then it was easy to add in the second slab. I love it. Interestingly enough, I was initially sleeping on just the hard 3″ and did fine with it, however with the top firm layer, it’s much more luxurious. I truly love it!!! – S.K., Washington