The ST9 is a striker fire polymer frame pistol with a host of features. These features include ambidextrous magazine release, and frame safety, 3 dot adjustable low profile sights, interchangeable backstraps to customize your fit, front and rear serrations on the slide to make it easy to manipulate the slide, and picatinny frame rail to add your favorite accessories. The rear of the slide features a red flag indicator that shows when the pistol is cocked and loaded. When the trigger is pulled, the red flag disappears to show the gun is not loaded and safe.