I’m selling a Heckler & Koch Model HK 4, a highly collectible and innovative pocket pistol first introduced by H&K in the mid-1960s. Designed for versatility, the HK 4 was one of the first pistols to feature an easily interchangeable barrel system, allowing shooters to switch between multiple calibers without tools. This made it a revolutionary firearm for its time. I only fired the .22LR barrel, while the .380 ACP barrel has never been shot. Original matching serial number boxes (Excellent Condition) Includes all original paperwork