Specifies the values for single- and triple-hole mounting of these switches for use in nominal 28 V d. c. and 115/200 V three-phase, 400 Hz a. c. systems. They are environmentally sealed and suitable for higher altitude and temperature conditions than are Class 2 switches which are sealed only at the lever entry. They do not have the positive action features of the Class 1 and Class 2 switches specified in ISO 1466.