2 Pcs Electronic Accessories: 1 x Relay Module & 1 x Battery Undervoltage Control Board This relay module is 5V active low. Relay output maximum contact is AC250V 10A and DC30V 10A. Standard interface can be directly connected with microcontrollers. This kit is compatible for IDE, Raspberry Pi and STM32 Working status indicator lights are conducive for the safety use 4-channel relay interface board, which can be controlled directly by a wide range of microcontrollers such as AVR, PIC, ARM, PLC, etc. It is also able to control various appliances and other equipments with large current. Widely used for all MCU control, industrial sector, PLC control, smart home control. Type: Electronic products Model Number: 12V Charging Controller Protection Board Application: Computer Operating Temperature: -40-+85 Supply Voltage: 12V Electronic products: For STM Colour:Blue Material:PCB Battery Undervoltage Control Board Size:40x29mm Relay Module Size: 76 x 56mm Package Contents: 1 x Relay Module 1 x Battery Undervoltage Control Board Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. This relay module is 5V active low. Relay output maximum contact is AC250V 10A and DC30V 10A. Standard interface can be directly connected with microcontrollers. This kit is compatible for IDE, and STM32 4-channel relay interface board, which can be controlled directly by a wide range of microcontrollers such as AVR, PIC, ARM, PLC, etc. It is also to control various appliances and other equipments with large current. Widely used for all MCU control, industrial sector, PLC control, smart home control. 2 Pcs Electronic Accessories: 1 x Relay Module & 1 x Battery Undervoltage Control Board Working status indicator lights are conducive for the use