The Skinnibelt is the best one out there.  I bought my first one at a retail shop, and my next 2 on Amazon. (After trying 2 other brands that didn't function nearly as well. The wider width of the belt also makes sure it doesn't curl around your waist; unlike some of the other similar belts out there.  The mechanism is a straight hook and loop, and takes up less space and is less bulky than other designs