I have designed these corsets to be the ultimate waist training/ extreme waist corsets. They have the same boning in the back and front as normal underbusts, but are double boned in the side with 9 spiral metal bones in each side a total of 18 spiral metal bones, and they have extra space for hips, this gives extreme support and they are made for cinching in a lot. They can be worn both by experienced corset lovers and as your first corset.