RAGE 50 lb Slammer Ball
This is an excellently constructed, durable product. I was initially worried that the ball would not hold up to repeated slams on a hard concrete surface, but after 3 weeks of regular use, it looks like it did when I removed it from the box. Using it will help train muscles that you don't regularly train, at least not by conventional weight training. Overall, I am really happy with this purchase.
February 9, 2013