Ebay offers AB Dolly Core Training System for $70.99 (reg $159.99) with free shipping.

Product Description:
The Ab Dolly is a great exercise system for toning and tightening abdominal muscles. No more lying on the floor straining your neck and back!
Traditional sit-ups and crunches are ineffective and time-consuming, not to mention a literal pain in the neck. Plus, they only work the abs in a small, limited range of motion. The Ab Dolly features flexibility and versatility so you can get a successful workout program every time you exercise! Various positions and movements allow you to focus on multiple areas so you are constantly working on all major muscle groups. You’ll get a full range of motion so you can work those hard to get at areas.
Get your heart pumping with cardio exercises like Mountain Climbers, Walking Planks, and Crunches. You can even target challenge areas like hips, butt, thighs, shoulders, arms, and upper back. This workout equipment is a functional abdominal training tool, with a unique design that allows you to also use it for plyometric training. You can stabilize one part of your body while working the other.
Convenient and versatile, the Ab Dolly allows you to work out anytime, anywhere, and get the muscle tone you want!
FEATURES

• Target your abs with the Ab Dolly abdominal exerciser to firm, tighten, strengthen and work out your muscles
• Challenge all 4 abdominal muscles in as little as 3 minutes per day
• Delivers great range of motion in any direction to target those hard to get areas
• Flexibility and versatility are the keys to any successful workout program and the ABDolly delivers
• Great for all ages and fitness levels
• Dimensions (L x W x H): 24 x 21 x 8.25 inches
• Weight: 7 pounds
• Manufacturer warranty: 2-year warranty