in an optical fiber connector member with a precision fit external conical surface at its front end , the fiber core is adjustable for centering during mounting by first fixing the fiber in an adjuster member inserted in the connector member , and bears with its nose against the inside of the connector member at a point somewhat inwards from the outer end of the fiber . the adjuster member pivots about its bearing point until the fiber core is correctly positioned , and is then fixed , with glue , for example .