Built around a modular concept so that a single pistol can be adapted to different needs and modes of operation, the Beretta Px4 Storm pistol is designed to make the most of the simple concept of individualized performance. The Compact model is sized between the full and sub-compact models. It adopts the rotary barrel design of Beretta's larger pistol, but with a shorter and proportioned slide and grip. This model also introduces an ambidextrous slide stop lever. A high magazine capacity is maintained, with 15 rounds in 9mm. The Compact models accept the full size magazines as well, increasing capacity to 17 or 20 rounds in 9mm. While the ultimate goal is comfort and ease-of-use, the Storm Compact will never feel oversized with a barrel length of just 3.2 inches.