Results of recent tests made under the specifications given in Class D for cut-outs, switches, conduits, wires, circuit breakers, fuses, etc., can be seen at inspection offices, and should be consulted in all cases where any doubt exists as to the ability of any particular device to successfully meet the requirements given. Copies of laboratory reports on all devices can be obtained by architects, building owners and contractors by addressing the Electrical Bureau of the National Board of Fire Underwriters at the Chicago office, No. 157 LaSalle Street, to which address new devices, or devices on which tests are required, should be sent.