The rotating slip ring is insulated from the shaft by a laminated plastic bushing. 旋转滑环是用片状塑料衬套与轴绝缘的。
The bell and spigot ends are normally jointed by using a rubber ring gasket. 钟型和套管末端通常用橡胶圈接口。
From this time Takahashi used a compression ring ocular holder to provide precise centering of the ocular and optics of the telescope. 同时，高桥在目镜的套管中使用了一个压缩环来保证目镜的中央位置以获得良好成像。
