This photograph documents a piece of electrical support equipment - a cased step-down transformer manufactured by Burton Equipment Co., paired with a fuse holder, terminal block, and relay unit - of the type used to power radio, radar, or other ground-based systems on a military installation. Photographs like this one were part of routine technical documentation kept by Air National Guard maintenance and supply units to record equipment condition, wiring configuration, and inventory status during the 1950s and 1960s. Project: 218663