Ab Tightener II will harden, flatten and strengthen your abdominal muscles in one smooth, rhythmic, impact free motion. Lateral pivot lets you move from a full crunch to an oblique crunch in one easy motion. No more hurting your knees or straining your back. Adjustable tension allows you to get stronger with each workout. Great for any fitness level.

• Tension collar with 3 levels of resistance.
• More effective than traditional crunches.
• Fitness Guide Included.