Features:1: Widely used2: Stable performance3: Maximum working current: 15A4: The operation is simple and easy to understand5: According to requirements, two options are availableDescription:Since the motherboard does not burn and download chips, this product needs to use the T-U2T automatic downloader to upload the program. If you don't have a T-U2T, you need to purchase the matching version before you can upload the program. If you already have a T-U2T, you Only need to have a T-U2T automatic downloader to be compatible with T-U2T series products, no need to repeat purchase.MCU: ESP32-Wrover-B FLASH: 4MB PS RAM: 8MBCommunication protocol: UART, SPl, l2C, CAN, l2S, SDIOWireless protocol: Wi-Fi: 802.11 b/g/nfor Bluetooth: V4.2 BR/EDR and BLEOnboard functions: four groups of relays, optocoupler isolation, 16 expansion IOHRS4H-S-DC5V relay: standard power consumption: 360 to 450 mw1, K1 relay: I0212, K2 relay: I019 four blue LEDs3. K3 relay: I0184. K4 relay: I005 relay working indicatorMaximum response/release time: 8ms/5ms Maximum operating current: 15AExternal power supply voltage input range: DC 12~24V Working temperature: -40~80℃Support T-U2T downloader:Can be connected to use T-U2T USB to serial downloader, which is convenient, fast, safe and beautiful. It can also be directly powered by Type-C USBYou can choose:1 X T-relay four-way relay 2 X pin header1 X T-relay four-way relay 1 X T-U2T downloader 2 X pin header