I ordered this product because I tuck in my shirt about 50% of the time, as I like the look of a tight tucked-in shirt. Though with that comes the constant retucking (or checking if I need retucking) after practically every time I sit down/stand up.Seeing this product I had high hopes that this would solve my problem.The shirt stay is plenty wide and elastic, it also has rubber circle grips reminiscent of those found on high-grip hand gloves.I have a size 30 waist and I found this to need a major adjustment to get this to fit correctly. It also took me a minute to figure out how to adjust.I put this through many standard tests, sitting down/standing up, raising arms, and touching toes.The product is like a belt on the inside of your pants to hold the shirt in place. It does noticeably work better than without one on most tests. What I started to notice though was a time or two the shirt stay itself came above the pants line when raising arms. Though I was testing this product, I do sometimes now check to make sure the shirt stay below the pants line.The verdict is still out overall, but the product is described and there is a noticeable difference in how well the shirt stays tucked in through the normal course of a day.