I have eight each Signal Corps C-75348 25 foot extension cords for use with telephones or radios. One end has a U-77/U connector and the far end has a U-78/U plug. Use these on darn near anything that you want to be at least 25 feet away from that utilizes the above hardware. Brand-new surplus, $15 each plus postage. Steve Hilsz jydsk at tds.net