This is a used item I received. It's an old item, but I've been using it while replacing screws. You can adjust the angle, knees, waist, chest, and other positions. I used it from around the 4th grade of elementary school to junior high school. Since I didn't purchase it, I don't know the exact size, but there are many screw holes, allowing for adjustments. There is some damage to the left side of the waist belt, making it difficult to fasten, but it is still usable. This is being sold for almost the cost of shipping, so I would appreciate it if you understand.