Description: This is a 4 port USB hub for Raspberry Pi Zero / Zero W, provides more USB capability to your for Pi, what's more, it features USB to UART converter for easy serial communication. The size of the board is designed to perfectly fit for the Zero, it can also work with any other versions of the for Pi. Specifications: Operating Voltage: 5V Dimension: Approx. 65 * 30 mm / 2.6 * 1.2 inch Mounting Hole Size: 3.0mm Package Weight: About 74g Package Contains: 1 * USB HUB HAT 1 * Micro USB Connector 1 * Micro USB Cable 1 * Screws Pack (2pcs) How to use: Take for Raspberry Pi Zero W as an example: 1. Plug the module to the 40Pin GPIO connector on the for Zero Board. 2. Plug the Micro USB connector to both the micro USB ports on the for Zero W and the USB HUB HAT. 3. For serial connection: connect the "USB to UART" port to your PC with a USB cable and the LED will be turned on. Then install the CP2102 driver on your PC. Now you can access your for Pi using serial connection (you should enable shell and kernel messages on the serial connection). 4. Attach USB devices to the USB1~USB4 ports and the corresponding LED will be turned on to indicate working state. Note: 1. There are two micro USB ports on the USB HUB HAT. Only the "USB HUB" (but not "USB to UART") connector is used for USB expansion. 2. You have to attach the USB HUB HAT to a for Raspberry Pi B+/2B/3B with a USB cable although the module can be attached to a for Pi Zero W with the Micro USB connector. 3. If you cannot access your for Pi using serial connection, try to enable the serial option in "sudo raspi config".