Markwrote a review of Nite Ize S-Biner SlideLock on January 6, 2016
Familiarity: I've used it several times
I like to keep my keys on separate rings and only take what I need. I used to use a non-locking 'biner and every now and then i would find a loose key in the bottom of my pocket. Just picked up a couple of these and can already tell they will be way better for my needs. The locking mechanism is pretty secure, yet still easy enough to unlock that i can switch out the keys based on my needs.