定义FS型连接器族的标准接口尺寸，该连接器族是插头和适配器配置的双工连接器集。插头有一对标称卡套直径为2.5 mm的圆柱形弹簧加载对接卡套。光学对准机构是包含在适配器内的刚性孔或弹性套筒。它包括一个手动释放的闩锁联轴器。插头具有多个键槽布置，适配器具有多个键配置。键控方案是排他性的，用于将插头和适配器之间的配合限制为特定的键组合。

Defines the standard interface dimensions for the type FS connector family which is a duplex connector set of plug and adaptor configuration. The plug has a pair of cylindrical spring loaded abutting ferrules of 2,5 mm nominal ferrule diameter. The optical alignment mechanism is a rigid bore or resilient sleeve contained within the adaptor. It includes a hand-released latch coupling. The plug has multiple keyway arrangements and the adaptor has multiple key configurations. The keying scheme is exclusionary and is used to limit mating between plug and adaptor to specific key combinations.