zone ii meaning in English

二号核突击警报地带

Zone ii diffusion
扩散二区
Explosion - proof speaker used in explosive gas and hazardous areas zone i and zone ii , also suitable for the high noisy industrial site , the load of the power , matching with the power output to obtain the best output effect
防爆扬声器可用于具有爆炸危险的i区, ii区场所,同时适应高噪声的工业场所,是功放的负载,要与功放输出相匹配,获得最佳的输出效果