ENTES SSRC-04 Rail Mounted Liquid Level Control Relay.
It is designed to control the level of conductive liquids in tanks, preventing motors from running dry in applications like wells, wastewater treatment, and pump stations.
It offers features like voltage protection against over/under voltage, phase loss, and phase sequence errors.
The SSRC-04P (a variant) features socket mounting for quick and easy installation without tools.
It is available for purchase from various retailers, including Rapid Electronics.