The P-11 is a semi-automatic, locked-breech, DAO, pistol, chambered for the 9mm Luger cartridge. Ten round and optional twelve round magazines available. The Kel- Tec P-11 is compact and lightweight, thanks to its locked breech. Its ergonometry, perceived recoil and practical accuracy are comparable to much larger guns. The P-11 is especially well suited for plain-clothes police officers, security personnel, or as a secondary weapon for military service members. 

The P-11 has six main component groups: barrel, slide, frame, firing mechanism, grip, and magazine. The barrel is made of SAE 4140 Ordnance steel heat treated to 47 HRC. The slide is also 4140 steel, and contains the firing pin and the extractor. The rectangular frame is machined from solid 7075-T6 aluminum and houses the firing mechanism. The trigger connects via a transfer bar to the hammer and operates in Double Action Only. The hammer is driven by a novel free floating extension spring. The light weight firing pin transmits the energy of the hammer to ignite the primer. The functioning of the mechanism surpasses all applicable SAAMI safety standards. The grip is made of the ultra high impact polymer DuPont ST-8018. The grip also forms the magazine well and the trigger guard.