Specification: Origin: Mainland China Product weight: 20g Product size: About 52.8x32x18mm/2.07x1.25x0.71 Coil voltage: 5V/12V Instructions for use: 1. Connect the corresponding direct power supply according to the voltage version 2. According to the requirements of the wiring diagram, the power supply cannot be connected in reverse. Although there is a protective circuit, it cannot be connected in reverse for a long time 3. The product uses a voltage regulator (5V without a voltage regulator) to generate slight heat, which is a normal phenomenon. Long term operation of the relay also results in normal heating, which is a normal phenomenon Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement. Included: 1 x Relay Module 1. Versatile Usage: The relay module can be used to control various household appliances, lighting fixtures, and factory equipment, making it a valuable tool for a range of small-current high-voltage products. 2. Reliable Performance: This module utilizes a double-sided PCB design, single-chip microcomputer control, and an anti-interference capability that makes it significantly more reliable than CD4013. 3. Powerful and Stable: With its large-power voltage regulator and sufficient heat dissipation holes, this module can work stably and reliably for long periods. 4. Safe and Protective: Equipped with a reverse power supply protection diode, this product can withstand short-term reverse power without damage.