"X-Ray In Use" replacement lenses. Order 7641-A1 for wall mount orientation. Order 7641-A2 for ceiling mount orientation. The Edwards 7641 & 7641R Series Dome Stations are used to visually indicate the placement of calls from a connected pull station. Stations are available with 1, 2, or 4 lamps; the domes, available in white or red, are designed with barriers between the lamps to prevent visual interference of signals. The 7641 & 7641R mount in a standard single or double gang box with a plaster cover and a minimum depth of 1 1/2" (38mm). Boxes and plaster covers not supplied. For use above entrances to areas equipped with a call station. See 7302 Series.