I was skeptical to buy a 3D printed piece of grip equipment at first. After owning and using it for a while I can say that making this device out of anything other than plastic would be overkill, cost more for the end user and not add any real benefit. I was also concerned that a lack of grip on the surfaces your fingers touch would make things slippery but it's a non-issue. With all the force being applied inwards, there's no slipping. If someone wanted to, they could easily add some adhesive backed sand paper, but it's not needed. Overall, it's a simple, very well executed tool. You can tell by the shape and dimensions that the inventor is very well versed in grip tools. Only small drawback is that it does produce kind of a rub/squeak sound when used. It's not super loud, but not the kind of thing you could use while watching tv with the fam. It's unique in that I don't know of anything else that works this type of grip that is easily portable: it's about the size of a can of soup is light weight.