The current USG variant is offered with fully adjustable sights Of FN Five Pistol

The Five-seven is a full-size semi-automatic delayed blowback pistol. Polymers are extensively used in its construction and even the steel slide is encased in a polymer shell. The barrel is hammer-forged and chrome-lined, with a total length of 4.8 inches and a rifled length of 3.7 inches. The barrel has eight grooves with a twist of 1:9.1 inches, right-hand. The pistol is noted for being very lightweight, weighing only 1.3 lbs empty or 1.6 lbs loaded.

The current USG variant is single action with a trigger pull of 4.4 to 6.6 lbs. It has an M1913 accessory rail and a magazine safety mechanism that prevents the weapon from firing without a magazine inserted. The grip is extensively stippled and the trigger guard is elongated to facilitate firing while wearing gloves. The pistol is currently offered in FDE (Flat Dark Earth) and ODG (Olive Drab Green) frame finishes in addition to the standard black
Particularly significant to the design of the Five-seven is the 5.7x28mm cartridge created by FN for use in it. This cartridge weighs roughly half as much as a typical 9x19mm Parabellum cartridge, allowing extra ammunition to be carried more easily. It also exhibits a flatter trajectory and produces roughly 30% less recoil, improving controllability.

One of the design intents of the SS190 variant of this cartridge (not sporting variants) was that it have the ability to penetrate Kevlar protective vests such as the NATO CRISAT vest. In testing conducted by Passaic County, New Jersey Sheriff's Department, the SS190 penetrated 11 inches in bare ballistic gelatin, and penetrated 9 inches in gelatin protected with a Kevlar vest. The SS190 and similar 5.7x28mm projectiles have been shown to yaw ("tumble") in testing in ballistic gelatin and other mediums, using the .850 inch projectile length to create a larger wound cavity. However, some are skeptical of the bullet's performance, questioning whether this behavior is sufficient to overcome the bullet's small diameter.

Since the SS190 projectile does not rely on fragmentation or the expansion of a hollow point, the cartridge and gun are considered suitable for military use under the Hague Conventions of 1899 and 1907, which prohibit use of expanding or fragmenting bullets in warfare