快装视镜 ball type sight glass
卫生四通视镜 cross sight glass
一体视镜 sight glass with light
直通试镜 sight glass
内开式带斜边椭圆人孔 Ellipe manhole cover
卫生级方形人孔盖Sanitary square manhole cover
卫生级人孔盖YAC型manhole cover (model YAC)
卫生级椭圆形人孔盖Sanitary manhole cover (model YAB)
卫生级压力圆形人孔Sanitary pressure manhole cover with glass
卫生级圆人孔Sanitary manhole cover
