This is a fantastic invention and I recommend this particular product to those mommies out there that don't want to spend the money on maternity jeans.  It's very comfortable and really does keep your jeans up when unzipped and unbuttoned.  I bought another product and was not happy with it at all - this really stretches and moves well with your expanding tummy.
Great for those who still fit in normal jeans, just can't zipper or button them.