Grip Strength Trainer, 100LB-300LB Metal Hand Grip Strengthener, Non-Slip Heavy-Duty Finger & Forearm Exerciser, Hand Gripper for Athletes, Hand Rehabilitation Exercising

I have the 100lb COC and Iron, as well as different 100lb grippers (adjustable, ring).This gripper is slightly harder than 100, but mostly because it's wider at the bottom so artificially harder to get a grip on. I don't have tiny hands, all the other grippers work fine.Furthermore, the foam pads turn slightly as you close, altering your grip.I ditched the foam, added some hockey tape, and good going. The gnurling is meh, and the grips themselves are narrower than others, so the tape evens this out.Regular grip is 3 stars.Inverted grip is 4 starsHolding it closed for prolonged amounts of time is 5 stars. The spring is strong.