When I backed these on Kickstarter, I was intrigued by the idea, but wasn't sure how they would actually work in practice. That's why I've delayed writing a review until I had used them/it for a while. (Full disclosure: I'm getting a discount offer as an incentive to write a review, but what's in the review is what I would hav written anyway.) The Clip really works. I do a lot of research at the British Library, and used to put a standard glasses case with reading glasses in the clear plastic carrier bag you have use there, with all the other stuff. I decided to try the Clips instead of the case. To be honest, I expected the Clips to get knocked off when the carrier bag was put in and out of the pannier on my bike, or during the ride up to town, but was pleasantly surprised that they didn't. I've now started putting my glasses in pockets with the Clips on, which I wouldn't have done with a bulky glasses case, and again they have stood up to it really well. The only improvement I could think of for the design might be to make the diameter of the key ring they sit on slightly larger, but it might already be the optimum size. These are actually one of those products that just work.