The Model 1901 and 1905 automatic pistols were the final development of the Mannlicher system. In this iteration they used internal magazines, a straight walled 7.65mm cartridge, and a delayed blowback system in which the slide had to overcome a spring-loaded wedge before it could open.
The Model 1901 was a compact version with an 8-round magazine, and the 1905 was a larger frame with a 10-round capacity, although both use identical mechanisms. The guns were moderately successful on the commercial market, although the only military adoption of the design was form Argentina, which bought about 6,000 of the 1905 model guns. These were surplussed onto the US commercial market in the 1960s, and are generally distinctive for the bright spot on the right side where the Argentine crest was ground off prior to sale (although some have been refinished to hide this).
Both the 1901 and 1905 are very comfortable, sleek and elegant guns to handle and fire.