I've got a nice dual one... it's made a few fellas cum simply from turning it on, and on just 'medium speed' at that!
I like this note from the Trojan site: "Note: The Vibrating ring is not available in Alabama, Colorado, Georgia, Kansas, Louisiana, Mississippi, Texas, and Virginia."
Translation: It's not legal for grown adults to buy anything that might be used for s-e-x in these states, since sex is icky and dirty and makes you go straight to hell.
Well, I can only guess it is like, and it actually was called this, the happy beaver vibe I bought a few years ago. It consisted of a ring that goes around your johnson and a little extension that went up for better clitoral stimulation. My Gf (at the time) loved it....I knew I was in for it when she'd walk into the room twirling it around her finger lol.
The battery is internal with a simple on/off button on the end of the vibrator unit. Battery is good for about 20 minutes.
Try looking in Shopper's Drug Mart. In the store I found it in (out west), it was on the shelf beside the condoms (not on a display hook and not at eye level). Not sure if I had missed them in the other Shopper's that I looked in.
The lady I was with liked it very much especially since she could control how much contact she made with her clitoris. She experienced a very strong orgasm in CG without much effort from either of us. She was less enthused about the condom that comes with it - she didn't like the low-latex condom provided in the package. Overall, it was a good investment of $10.
A minor aside, Durex also has a vibration ring but is not currently marketing it in Canada.