Heizer's 'Pocket 45' pocket pistol is constructed of aerospace-grade stainless steel with a fixed barrel for less moving parts and a snag-free design for conceal carry. This ultra-slim semi-auto is just .8" wide and weighs 25 oz. With it's revolutionary barrel-under the guide rod configuration, less recoil is felt by the operator. Chambered in .45 ACP, the PKO carries a 5 round capacity with the flush magazine.

https://www.gcarms.com/handguns/pre-owned-3-7298/heizer-ckh45blk-pko-45-single-45-automatic-colt-pistol-acp-275-barrel-51-rounds-stainless-steel-gripframe-black-4977953