I didn't know that! It truly is possible to have police rings personalized.
Now, you would ask why the sudden interest? Nothing special actually. I just thought that during Christmas and with friends or family that are in the service perhaps a ring is an interesting gift. To have it done according to an individual policeman's preferences - his own emblems, engraving, and stone color - will make it truly special. The gift giver can also choose what metal to be used (which is of course according to what he thinks the receiver would like) and they vary from steel, silver, and gold.