Oh finger vibes 
sorry, had a brain dead moment.
Ive got The excite one, (review here) which i like but should use more. Its a little bulky and takes hearing aid betteries but its feels good, especially when you flip it round to the back of the finger so you get the vibrations running through the fingers (i prefer skin texture to silicone if i get a choice).
People mention the ignite and glover ones too. Personally i think theyr a nice thing to have in the toolbox, would i pick them over a bullet vibe? no, you can buy a much better bullet than most of them (there are exceptions out there). But if your partner is good with their fingers i think they can be alot of fun
Theres also This which seems to have some good reviews. Not quite the same thing, but pretty close