The Square D 8501 NR-52 Double Tier Relay Socket is a reliable and efficient DIN rail mounting device designed for AC current relay applications. With a coil voltage range of 251-300V, this black socket is suitable for interior use in electrical wiring setups. This single pack socket is specifically dedicated to the Square D brand and model, ensuring a perfect fit for your relay needs. Built for durability and functionality, this relay socket is a must-have accessory for any electrical equipment and supplies project.