Burger Grips with Hooks 3.5"-pairIf Kung Fu Grip is what you're after, the burger shape of these grip strengthening metal masterpieces is what you need. The 3. 5" diameter shape fits into your palm amazingly and allows your fingers to just go over the top and grip on like the talons of a bird of prey. For reference, my hand measures 7 7 8" from tip of middle finger to first wrist crease. There will be options for a 4" and a massive 4. 5" soon.