sight glass
... reflector sight 红点镜 ; 反射瞄准镜 sight glass 视镜 ; 观察孔 ; 观察镜 ; 窥镜 far sight 远视 ; 透视 ; 视界术(炉石传说卡牌) ; 远景 ...
observation mirror
... projecting mirrorn.投射镜 observation mirrorn.观察镜 mirror-like tonguen.镜面舌 ...
slide viewer
... slide rule 计算尺 slide viewer 观察镜 slider (1)滑块(2)滑板,滑座(3)滑尺 ...
inspection glass
... inspection glass for oil level 油位观察镜 inspection glass 观察镜 inspection hole cover 检查孔盖 ...