Only Kazdra (any type), elves, and other majestic and smart races can wear this ring and have it work, for, it was made by them to only work on a Kazdra. What this ring does is makes the Kazdra wearing it have the smarts of the smartest Kazdra to ever exist: the very first one plus their own. This intelligence makes some Kazdra able to move small pebbles or small metal forks with their mind. This, however, is very rare and only happens to the smartest of the smart bunch. Currently, it is being held in containment, but, maybe that will change next in your campaign.