The Bogen Models SBA225 and SBA325 Room Selector Panels are designed for use with Bogen Multi-Graphic® and Multicom 2000® Systems.The SBA225 is also used in Bogen's PI35A and SI35A Power Intercom systems. These panels provide call annunciation (using LEDs) and tone signal in addition to room selection. The panels use three position, four-pole lever-action switches with positive detents. In the SBA225, these switches are used to selectively connect up to 25 speaker-equipped locations to either a PROGRAM, OFF or INTERCOM channel. In the SBA325, the switches selectively connect up to 25 speaker-equipped locations to either a PROGRAM-A, OFF, or PRO-GRAM-B channel. The INTERCOM channel is selected by means of separate push on/off switches. Channels are clearly identified with color-coded guide-lines in accordance with the Multi-Graphic operating method. Calls from staff stations are initiated by a momentary depression of a call origination switch, which lights the corresponding LED on the selector panel and sounds a tone signal to bring attention to the call. The LED remains "on" until the call is acknowledged, at which time it is automatically cancelled. The room selector panels permit maximum roomselection to be accommodated in a minimum of space. Each selector panel also has provisions for accommodating the add-on Bogen Model TZMA Time Zone Module Adapter, providing up to six zones of time signalling, and/or the Model SCR25A Call-In Module, providing the circuits necessary when using call origination switches which do not contain silicon-controlled rectifiers. The room selector panels are designed to provide years of unfailing trouble-free operation. The switches are ruggedly constructed to withstand heavy usage and are designed with positive detents to assure properpositioning. Lever switches are self-wiping to prevent erratic operation, and precious metal contact surface sensure low contact resistance and consistent operating reliability. Switch handles are permanently affixed to the switch shafts, eliminating trouble some replacement problems. Further assurance of trouble-free operation is provided by the LEDs, which are designed to give years of efficient service.