four-pole change-over device 四极转换器件

pump auto-change over device 泵自动切换设施

power supply change-over device 电源转换装置

roll change over device 换辊装置

change-over device 转换器

video change-over device 视频转换装置

chain change-over device 布铗链换向装置

multichannel change-over device 多通道切换装置

coaxial change-over switch device 同轴开关转换仪