The Model 448 Output Relay Board provides electromechanical relay contacts for the Model 404 or 408 Liquid Level Sensors, allowing those models to be used as a control device. The Model 448 consists of a power supply and five relays on the surface-mounted printed circuit board. Four of the five relays are used with the Model 404. All five relays are used on the Model 408, refer to typical application. Some liquid level control applications may not require the alternating control, HOA switches, or run-time meters (see the Model 403 or Model 407 data sheets). The Model 404 and Model 408 Liquid Level Sensors uses the Model 448 to meet the needs of direct relay control applications.