Thanks to Harbinger for sending me the following 10 pound fitness ball to test out. Based in Napa, California, Harbinger is the industry leader in fitness accessories. Harbinger Products are available at most major independent, specialty and general sporting goods retailers nationwide.
The weighted fitness balls come in 2 pounds, 4 pounds, 6 pounds, 8 pounds and 10 pounds. They contain an adjustable veclo strap so that you can wrap around the back of your hand. It is designed to be easily grasped and used. It's a good alternative to metal free weights and helps improves strength and endurance by helping to isolate specific muscle groups during training. It's made from soft, pliable PVC.
In addition to the fitness balls, Harbinger also sells gloves, wraps and straps, and training aids, such as ropes, bars and belts.