It differs from M1911A1 also in other details. Unlike M1911, the barrel was not cammed by a link, but by a ledge of sorts, which contacts a portion of the barrel and forces it down as it is moved rearward with the slide by the recoil force, similarly as in Browning's FN Hi-Power pistol and Spanish Ruby 0.45 ACP. The design was generally based on American firearms inventor John Browning's Colt M1911A1, operating on the short-recoil principle, with the barrel being cammed down and away from the locking lugs in the slide. Considered by many to be one of the finest handguns ever produced, it is highly prized among collectors of firearms. Originally designed by Piotr Wilniewczyc and Jan Skrzypiński in 1930 at the Fabryka Broni (Arms Factory) in Radom under Director Kazimierz Ołdakowski, it was adopted in 1935 as the standard handgun of the Polish Army. 35 Vis, German designation 9 mm Pistole 35(p), often referred to as the Radom in English sources) is a 9 mm caliber, single-action, semi-automatic pistol.