The submachine guns 23 and 25 (originally model 48a/b) and the Sa 24 and Sa 26 (popularly also called pump) were the main infantry weapons of the Czechoslovak Army from 1948 to 1958. They use a 9 mm Luger cartridge (Sa 23 and Sa 25) and a 7.62 × 25 mm Tokarev cartridge (Sa 24 and Sa 26) and are equipped with a dynamic (unlocked) slide. They can fire single shots or bursts.