I never would have thought to add this into my gym bag until recently. I recently been shaving my calluses down on my hand very often, but I would have major pain when gripping for a few days following. I was introduced to these bad boys and it was a game changer for me. Im on the pull bar longer than usual AND my hands stay locked in position. Meaning there is no slipping off the bar. Im in love with my Jaw Hand Grips!