The Nano has a connector bar on the right side of the gun that connects the trigger to the sear. A projection on top of the connector bar pushes the bar down and out of engagement with the sear when the slide is out of battery. When the slide reciprocates, as it goes forward the tail of the striker engages and the sear holds it in a half-cock position. When you pull the trigger the sear rotates backward, pulling the striker even further back and then releasing it. If the sear does not hold the striker at half-cock, the gun cannot be fired.
There are three safeties on the Nano. A lever on the front of the trigger must be fully depressed before the trigger can be pulled. Then there is a striker block pin, which is pushed up as the trigger is pulled (and is visible in front of the rear sight). Lastly, a striker deactivation button on the right side of the gun allows the striker to be released from half-cock without pulling the trigger. This enables disassembling the gun without the need to pull the trigger.
The stainless steel slide features a black nitride finish, which provides extra protection from wear, moisture, salts, and other unpleasant things a careless owner or the environment might expose it to.
The pistol is fitted with a set of low-profile, three-dot sights. These are held into cuts in the slide by small set screws that allow the owner to change the style of sights. Beretta also offers Trijicon night sights on the Nano.
Breech locking is accomplished by a method used on many of today's pistols. The barrel and slide are locked together by the barrel hood moving up into and bearing on the front edge of the ejection port. Upon firing, the slide/barrel unit reciprocate to the rear locked together and after a short distance the barrel is cammed down, allowing the slide to continue rearward, extracting and ejecting the spent cartridge case. The recoil spring then pulls the slide forward, stripping the next round from the magazine and chambering it. As the slide goes into battery, the barrel is cammed up, locking it and the slide together again.