SR504-4 Switching Relay，SR-504-4，4 Channel Relay Module

【Switchable Priority】SR504-4 Switching Relay, compatible with Taco switching relay. It features diagnostic lights, fuse-protected outputs, sealed relays, simplified wiring and switchable priority for stable and flexible operation. 【Wide Application & Stable Sealed Relays】This 4 zone switching relay fits most household hydronic systems and provides a reliable alternative to Taco relays. Stable sealed relays ensure consistent performance. 【Flexible High & Low Level Trigger】SR504-4 Supports both High-Level and Low-Level trigger modes via a configurable jumper for each relay. 【User-Friendly & Safe Design】Features clear screw terminals for secure AC/DC wiring, a transparent cover for safety, and status LEDs for each channel (power and relay engagement）. 【Reliable Quality & Warranty】Rigorously tested with 6-month warranty and free return & replacement service for reliable performance and customer support