The HF49FD/0051H11 power relay is a 4terminal normally open SPST device designed for reliable switching of low to medium power loads. This listing includes 10 pieces. Each relay is rated for onstate currents up to 5 A and supports switching of up to 30 V DC or 250 V AC. The coil is 5 V DC, indicated by the 005 in the model number, enabling control from common 5 V logic. Key benefits Simple NO SPST switching: easy to use for turning loads on and off with a single switch path. voltage and current versatility: suitable for both DC and AC loads up to 30 V DC or 250 V AC at a 5 A maximum. Lowvoltage control: 5 V DC coil enables control from microcontrollers, PLCs, and other lowvoltage control circuits. Minimal footprint for compact designs: fourterminal configuration supports straightforward integration in compact assemblies. Value set: 10 relays per package, ideal for multichannel applications or rapid prototyping and production builds. Key attributes Model: HF49FD/0051H11 Configuration: 4terminal normally open SPST Coil voltage: 5 V DC (indicated by the 005 in the model) Contact ratings: 30 V DC, 250 V AC, 5 A Type: power relay in a compact fourterminal form Quantity: 10 pieces in this package Applications and use cases Home and building automation: control a 120 V AC lamp, fan, or other device from a 5 V control signal, with isolation between the control circuit and mains load. Electronics and enclosure control: switch a 12 V DC accessory or auxiliary supply within a system, keeping the control circuitry isolated from highervoltage loads. Automotive and offgrid systems: manage 12 V DC loads or batterypowered devices (within the 5 A rating) using a 5 V control signal from a microcontroller or portable controller. Notes This description reflects the specifications implied by the model HF49FD/0051H11: normally open SPST, four terminals, 5 V DC coil, and contact ratings of 30 V DC / 250 V AC at 5 A. For exact coil resistance, power consumption, and physical dimensions, refer to the official datasheet for the HF49FD family and the specific 0051H11 variant.