A friend of mine bought some of these from a different seller, and after she showed me some of the features they have, I thought it'd be nice to have some for when we go to crowded events with the kids. However, the ones that she showed me, while they looked identical to these, were actually much different for a variety of reasons. Ultimately, these ones were a few dollars cheaper, so for that reason, I can't harp too much; however, the ones my friend had purchased had a rotating piece where the spring connects to the arm band so that they wouldn't get wrapped up or tangled when in use. Also, the ones she had purchased had a double Velcro feature for the child's bracelet, so they weren't as likely to remove it themselves/it would be harder for an attacker to remove (one Velcro strip went around the wrist, and the other went in the opposite direction over that one). Lastly, the other ones seemed to have a longer extension than these. On the plus side these are extremely durable. I put the child bracelet on and my husband pulled as hard as he could to test the Velcro and see if it would hold, and it did...plus some! Also, like I mentioned, they were slightly cheaper, I believe I paid $12 for a set of one pink and one blue one. & Lastly, they work! That's all that really matters, right?! As much as I was hoping these would have the features I listed above, they are still a great deal for what you get, and I can't complain too much! I'd recommend these to someone looking for that extra level of protection for their children....I've always been against using a "leash" for children, but with things getting as bad as they have been, it's nice to have the option for my kids to be able to run freely, while still keeping them at a safe distance. I feel like these are much less restricting than the leashes or backpacks, and with me wearing one as well, it doesn't seem as dominating as the alternative options. Honestly though, if it saves your kids life, it's well worth the criticisms!