Diamondback Firearms DB9, Semi-automatic, Striker Fired, Sub-Compact, 9MM, 3 Stainless Steel Barrel, Nickel Boron Coated Barrel and Slide, Black Polymer Frame, 6 Rounds, 1 Magazine DB0200P021 The Generation 4 DB9 comes chambered in 9mm and is dubbed as one of the smallest micro-compact 9mm pistols on the market. Its overall length of 5.73", overall height of 4.51" with the pinky extension base plate, and overall width of .9" make it the perfect carry option for a purse or pocket.