A Connector type which has a Taper sleeve which would be fixed to the Fiber optic cable. When this plug was inserted into its Receptacle the tapered end was a means for locating the fiber optic Cable in the proper position. With this connector cap, fit over the ferrules, rest against guided rings and screw onto the threaded sleeve to secure the connection. This was one of the earliest connectors used in fiber optic systems but is in little use at present.