The Body Solid Sel AB Mach Stack is an all 4-side welded that is Ideal for private & commercial use. It makes use of extra-tough, tear-resistant DuraFirm upholstery that is double-stitched. Other notable features include Fiberglass reinforced nylon pulleys with v-grooved channels, Nylon-coated, self-lubricating, aircraft-quality steel cables, Double, powder-coat finish protects against scratching, chipping and peeling. The Pro Club Line Ab Machine provides absolute isolation of the stomach muscles with its unique, variable resistance cam. This product is biomechanically engineered for smooth, comfortable, full range-of-motion cruching movement and designed for liming, flattering and isolating the entire abdominal area. It stabilizes your body for ab crunches beyond your body weight. Thus this product add up to workoud pleasure, safety and top performance.