This Lochinvar Pressure Switch is a critical component designed to monitor the pressure within your system and activate an electrical response when a certain pressure level is reached. The device features a 90-inch length, providing ample reach for various applications. The "NO" in its name stands for Normally Open, indicating that the switch's default state is open and it closes when the designated pressure threshold is exceeded. This pressure switch is identified by the manufacturer's code 100210101, which can be used for reference or replacement purposes. It's designed to work seamlessly with other Lochinvar products and systems, ensuring optimal performance and reliability.