New in box, never opened Our ab machine has cleverly hidden interlocking springs on each side that provides adjustable resistance,which can help you get back to your starting position, it's like having the hands to spot you, this is perfect for older people or anyone that's just starting out.The secret is ingenious patented design in the Wondercore smart is that it has precision dials on each side, which allow you to adjust resistance, delivering an amazing 24 pounds to 48 pounds of resistance per side. Precise adjustable resistance to dial in the exact type of workout that you want, whether you're a beginner or pro, Wonder Core Smart can target at stubborn midsection and get the results that you're The Wonder Core Smart exercise system is designed to provide a laser focus on your upper, middle and lower abs, and oblique muscles for a well-rounded workout you will feel all over. Exercise your arms, shoulders, midsection, thighs, legs. ab tuck, ab crunches, sit up, push up, forearm workout, scissor kicks, glute bridge, bicycling. You can target your core, do upper body, lower body and cardio all in one compact ergonomic design. 6 great exercises plus cardio to give you the ultimate total body calorie blasting workout. ab tuck, ab crunches, sit up, push up, forearm workout, scissor kicks, glute bridge, bicycling. 6 great exercises plus cardio to give you the ultimate total body calorie blasting workout.