This pack includes 20 pieces of G3MB-202P-5VDC relay modules. Compact 4-pin PCB relays designed for easy integration into control circuits and small control panels. Key benefits Reliable electrical isolation between control and load circuits for safer designs and reduced interference. Directly compatible with 5V DC control logic (microcontrollers, PLCs, driver boards). Variants for 12V and 24V coil versions are available in other listings. Rated for switching moderate AC loads: 2A at 240VAC contact rating suitable for lights, small motors and similar devices. Simple 4-pin PCB footprint for straightforward mounting, replacement, and integration in compact assemblies. Fast, repeatable switching behavior for predictable operation in automation and control projects. Important attributes Model: G3MB-202P-5VDC Coil voltage: 5V DC (this pack). Other coil voltages (12V, 24V) available separately. Load capacity: 2A at 240VAC Configuration: 4-pin PCB relay modules Form factor: compact PCB-mount design for tight spaces and panel use Typical use scenarios Home automation: switch room lighting or exhaust fans from an Arduino or Raspberry Pi-based controller while keeping mains isolation from the control board. Small automation panels: control pumps, small heaters or AC actuators in compact enclosures where a 2A switching rating is sufficient. Prototyping and education: teach relay-based control circuits and safely test AC switching in lab or classroom projects. Safety and usage tips Drive the coil with a suitable transistor or driver stage and include a flyback diode when switching DC coils to protect the driver. Keep switched current within the 2A at 240VAC rating and follow correct wiring and insulation practices. Use proper isolation and safety precautions when working with mains voltages. Package contents 20 × G3MB-202P-5VDC 4-pin PCB relay modules