a thick rubber instability mat, measuring 16'' by 20''? And if you know what it is, could you tell me where to buy it? i have been looking online and at stores and I can NOT find it...
well this one is pretty thick, kind of like a yoga brick but bigger? The doctor from the Biggest Loser designed a program using it, but i cannot find it...
Are you sure it's not a "stability" mat and not "unstability"?
A stability mat could be like a yoga mat or the thick ones that go under treadmills. Do you have a link or anything to the program that uses it?
I've seen several kinds of mats at Walmart.