 He was assisted by his brother Emmanuel, as well as two Austrian and Polish engineers, respectivily named Marek and Podrabsky.Holek quickly began work on the prototype of the Praha II and within a year the quartet had created an automatic light machine gun that was later known as the ZB.Before long, the Holek brothers abandoned the belt feed in favor of a top-feeding box magazine and the resulting weapon, known as the Praha I-23, was selected.