I purchased this on recommendation from a fitness store I have worked with before. They didn’t have this in stock, and it was less expensive on Amazon anyway, but of course, I had to assemble it myself. Important: if your lower back has any problems at all, you really should not use this chair without consulting with a physician or at least a trainer. You can seriously hurt yourself otherwise. Every piece of exercise equipment carries that warning, but it is particularly important for something that works your back muscles.QUALITY OF THE CHAIR:It’s excellent for a piece of home equipment. After proper assembly (emphasis on the word “proper”), it is sturdy and can hold a medium-to-large person very well. The foot rest is adjustable so that you can get the level of hyperextension that is good for you. This type of bench will help with lower back muscles and glutes when you’re in the downward-facing position, and will give you a great ab workout when you’re in the upward-facing position. I used to use one of these chairs back when I was a gym rat and always liked the intensity of the benefit I got from it. One reason I bought one now was that I have a desk job and a long commute in the car, so I need to do something for my lower back. This helps a lot, and having it in my house means I can do a quick spot-training whenever I want. It also doesn’t take up too much space, which is nice.ASSEMBLY:The assembly instructions are fairly comprehensive by today’s standards. I did a parts inventory before getting started, and I couldn’t find a couple of the smaller parts initially (one bolt and one knob), because they were already installed in their respective frame pieces, but everything was there. Make sure you understand which parts are which. There are three different sizes of hex bolts, and two of the sizes are only 5 mm different. The instructions say you should not tighten the bolts until after you have put the entire bench together, and that’s good advice. You will need a standard set of wrenches to assemble this bench. The instructions aren’t clear that you only need a standard set of wrenches – nothing unusual. I used a few different sizes, and I feel comfortable saying that an adjustable wrench would not be sufficient. There are a couple of tight spots where a clunky adjustable wrench probably wouldn’t fit. I also made use of my rubber mallet to “encourage” the plastic end caps and rubber grips into place. As you are going along, look at the diagram of the fully assembled bench so you can make sure you are inserting each piece exactly where it needs to go. I almost set the bench up backwards on the base, and that would have resulted in the bench toppling over when I used it. Assembly probably took me 2-3 hours, doing it by myself. (I’m an average-sized woman with reasonably good DIY skills.)