Snake in your pocket?
Recently introduced by the Cocoa, Florida-based gunmaker, the DB9 Gen 4, with a weight of just 13.4-ounces while maintaining a 3.1-inch stainless steel barrel that gives an overall length of 5.73-inches, Diamondback describes their gun as the “smallest and lightest” 9mm on the market. With a flush-fit magazine shoe installed, its height is 4-inches flat. The maximum width is 0.89-inches.
For the past couple of months, I’ve been carrying a DB9 G4 off and on as a backup gun and in situations where it is harder to carry a full-to-medium-sized pistol. In essence, it has been taking the place of my trusty old S&W J-frame, and with good reasons.

Here is a stack of the DB9 against the iconic pocket roscoe: The S&W J-Frame. As witnessed by this S&W M642, the DB9 is smaller and a tad lighter. Plus, it can carry seven rounds of 9mm as opposed to five of .38.

Further, the DB9 is downright skinny when the width is brought up and the Smith falls in alongside. Also, the DB9s barrel length and sight picture in both cases is an improvement, along with the faster reload.
Anyway, more on those size stack-ups in my column at Guns.com