This unique dual-function sitting ab machine and back machine allows you to exercise two major muscle groups (the stomach and back) for one great low price. The innovative plate-load design is based on health club single station machines. We even incorporated 2in x 4in mainframe steel from our commercial grade line of equipment for institutional quality. The full-range cam design has an easy-to-use pop pin that allows an additional 26 adjustments to increase and control your range-of-motion. Break-through technology lets you tighten abdominal muscles, strengthen your lower back and increase flexibility. Weight plate post is 1 inch diameter. Shown with Olympic Adapter Sleeve, weight plates, and collar, sold separately.