The use of mandrels in multimode insertion loss testing helps to ensure the proper launch condition into the fiber under test. By wrapping the fiber around the correct size mandrel, high order modes are stripped out and low order modes are spread out to achieve the desired launch conditions for testing. Each includes the mandrel and clip for holding the cable firmly in place during testing. Accepts jacket diameters from 1.6mm to 3.0mm and for use with both OM1, OM2 cable. When testing Corning CleareCurve fiber it requires a smaller 4mm radius mandrel which is available.