MLRR-3 Reed Switches Littelfuse MLRR-3 Reed Switches provide 200VDC at 20W switching with close differential characteristics. These Hamlin / Littelfuse reed switches are normally open with a 15.24mm long x 2.54mm diameter glass envelope. MLRR-3 features 10MΩ minimum high insulation resistance and less than 100mΩ contact resistance. This series is ideal for use in security, limit switching, office equipment, and light inductive load applications.