The PX4 Storm Type D is the double-action-only variant in the PX4 family. The thumb lever is vestigial and non-functional; every trigger pull is double-action only. The DAO configuration is preferred by some law enforcement agencies and jurisdictions that require a consistent trigger pull without manual safety engagement. Less common than the Type F. Type: Pistol Action: Semi-Automatic Caliber: 9mm Capacity: 17 Year introduced: 2007, Italy Weight: 27.7 oz Overall length: 7.6" Status: Active Intended use: Law Enforcement