The NDI-03H-V with DIP Switches/SIP Switches Dip switch Through Hole Type manufactured by Diptronics is a single-pole double-throw (SPDT) switching device with a range of three settings. This switch, which is also referred to as an on/off/on switch, has two basic positions: on and off, combined with a third position. The switch is a through-hole type, meaning that it is mounted in a PCB (printed circuit board) with its legs passing through and soldered to the board for a secure connection. The pole and actuator are designed to fit into a standard DIP (Dual In line Package) or SIP (Single In line Package) socket to provide a reliable electrical pathway. This switch is perfect for applications such as controlling power, selecting modes, controlling other devices, and controlling audio and video equipment.