DO NOT PANIC if you can't "slide" the sides into the base or the back of a chair, loveseat or sofa. I spent TWO days pulling my hair out and almost returned it. THE SLIDE-IN SYSTEM DOES ACTUALLY WORK. 1. DO NOT bother trying to slide an arm or back STRAIGHT DOWN onto a base. That won't work. Let's say you're trying to slide the side of a couch onto the base of the couch. HOLD the side but TILT IT so the top is touching your chest and the bottom is four inches away from your stomach. It's at that ANGLE. NOW try to slide the side into the bottom. Once you feel it start to slide in/take, THEN straighten up the side. EVEN BETTER, while you silde the arm down at an angle, have someone hold the base up at a similar angle from their end - not easy to do. Finally, here is a video on how to do it and notice the angle at which they slide it in at timemark 0:58 on: https://www.youtube.com/watch?v=hIm8ZuvPzFQ . Overall, good quality but the cushions are WAY too hard.