The TOA Electronics RS-150 single button indoor call panel substation is designed to be used with the N-8000RS or N-8010RS substation interfaces. The 4cm (1.57in) speaker provides clear audio and the single black call button allows for simple call-in operation. The call button can be programmed to report to any master station based on job specification. It requires 3-conductor shielded twisted pair (STP) wiring and mounts in a standard US dual gang flush or wall mount box.