In Czechoslovakia it was known as Praga PLDvK vz. 53/59 - "Ještěrka" (PLDvK Model 53/59 - "Lizard"). PLDvK stands for Protiletadlový dvojkanón = Anti-aircraft twin-gun. The system is optically aimed, and can only be used effectively during the day with good weather conditions. The gun can be dismounted and used independently of the vehicle. When Czechoslovakia imported one Soviet-made ZSU-57-2 for testing it considered it to be comparable to M53/59 which was the reason for which Czechoslovakia refused the Soviet SPAAG.