Jack, I have answered this question before but can not find the post. Way back I bought a small hand held battery job from an outfit in Texas, called UVtools. It worked great but ate batteries as all of these do, so I only use it when at a show or shop somewhere.
Two years ago I decided to upgrade and ordered their better unit, but they were out of stock and sent me the een larger unit. It is a beauty, and it shows all of the nuances that tagging has to offer. Their website is
www.ultraviolet-tools.com .
I also have a Raytech but am less impressed with it.
Peter