The ČZW-556 is an assault rifle of Czech origin. It is chambered in the 5.56x45mm NATO round and uses lever delayed blowback operation, previously used on the LCZ-B20 platform and the 2B-A-40/TKB-517 assault rifles. The lever-delayed blowback operation of the ČZW-556 increases accuracy, controllability, reliability and ease of maintenance of the weapon over gas-operation.