Why didn't these come out when I was young. Grip4orce is taking my training to a whole new level. Bigger guns, stronger grip, more strength with one simple attachment with resistance inside. I've purchase the regular flex and also the stiff flex resistance. I use regular on pull day and the stiff on push and arm day. I hitting muscle fibers I never thought I had. They say that no matter how old you get if you train your grip you'll never lose the strength in the hands. Never know when you might have to put a young punk in his place.