This is a Browning Model 35 "Baby Browning." It was not a terribly successful firearm, and from the history I've read, it was a deviation from the original John Browning design. It is tiny, and fits nicely in an ankle holster as a backup weapon. It is stamped "6mm," and shoots .25 ACP ammo. This particular piece was manufactured in 1968 (according to the serial number and information provided by Browning), and belonged to my uncle. When he died, I inherited it. I'd never seen one before. With one finger on the trigger, your middle finger holds the pistol's grip. That’s it. It jumps a little when I shoot it, and the slide will skin the web of my thumb if I'm not careful. If I were going to carry a backup piece in an ankle holster (I'm not) I'd probably choose a little .380. My everyday carry is a Glock 26, and I'll probably never carry this Baby Browning, but it is still an interesting piece, and fun to shoot if I take care to grip it right.