Integrated SD card reader (for card reading via USB) Integrated USB serial chip (used for Wi-Fi configuration through the serial port). USB toggle switch (between card reader and serial chip) 3.3V 600mA LDO (used when the WIFI module power supply is plugged into USB) Item Type: Module Model Number: SD-WIFI with Card-Reader Module Operating voltage: 3.3V (via ) / 5V (via USB) USB to serial chip: CH340E Maximum current: 600ma colour:Black Material:Plastic + Metal size:49.5mm x 24mm Package Contents: 1 x module 1 x USB cable Only the above package content, other products are not included. Note: Light reflection 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.