给你的耳朵一些假期吧! 

油位观测窗

windows for oil level check

Transparent opening to quickly check the oil level without having to lift the cover of noise enclosure. 

OTHER FEATURES
indicator light for operating statut of vacuum pump enclosure
工作状态指示灯
VACUUM TUBING AND CABLES GROMMET
可锁定全球适配航空插头
GRANT YOUR EARS SOME HOLIDAYS !