Fibrain Rapid Splice mechanic splices provide high quality fiber optic connections. They can be characterized by short termination time. Mechanical splice connection makes use of mechanical splice unit where 2 fibers are first inserted into the unit (fibers are set to the V-groove of the mechanical splice). The fibers are next aligned and then held in position by clamping parts. s. Index matching gel is added to the center of the mechanical splice ( at the supposed connection point of the two fibers) to ensure good Insertion and Return Loss.