IEC 61755-3-8:2009定义了直径为2.5mm和1.25mm的圆柱形复合套圈光学接口的尺寸限制和材料特性，以满足APC光纤到光纤互连的具体要求。复合套圈在端面接触区和套圈与套筒接触区使用不同的材料。每个区域的指定材料为套圈至套管接触区的氧化锆（ZrO2）和端面接触区的钛。由本标准中规定的材料制成的套圈适用于IEC 61753-1中定义的C、U、E和O类。

IEC 61755-3-8:2009 defines dimensional limits and material properties of a 2,5 mm and a 1,25 mm diameter cylindrical composite ferrule optical interface to meet specific requirements for APC fibre-to-fibre interconnection. The composite ferrule uses different materials in the end face contact zone and in ferrule to sleeve contact zone. The specified materials for each zone are zirconia (ZrO2) for the ferrule to sleeve contact zone and titanium for the end face contact zone. Ferrules made from the material specified in this standard are suitable for use in categories C, U, E and O as defined in IEC 61753-1.