The connectors are keyed to prevent mismating. A rigid shroud protects the ferrules from accidental damage, while a floating interface ensures consistent mating without stubbing. Different keying arrangements are provided to key the connector to different FDDI requirements. FDDI connectors are not restricted to FDDI applications. If performance isn't the issue it once was, ease of use is.
Some connectors use epoxy.
Other connectors do not require epoxy. The epoxy step, in particular, is seen by many as a necessary evil. Not only do curing times slow productivity, but speeding the process means additional equipment like curing ovens to lug around. Fortunately, epoxy-less connectors now offer reliable, fast termination. Epoxy-less connectors have slashed application time from 10 or more minutes to less that 2.