rental of sound equipment and related accessories, namely microphones, wireless microphones, microphone accessories, cables, cable connectors, signal processing equipment, mixing boards and consoles, amplifiers, communications equipment, speakers, speaker processors, video cameras, video monitors, intercom packages, paging packages, power distribution devices, tape machines, effect machines, taped sound effects, cases, computers, custom rigging hardware, signal analyzers, black boxes and custom interfaces, audio racks, speaker towers, and batteries