Features: 1.IO: bit expansion board is a powerful micro:bit expansion board, which leads to 19 PIN pins of the Microbit Board. 2.Each PIN pin has VCC and GND corresponding to it. You can freely switch VCC to 3.3V or jumper cap. 5V; with 3 independent 3V3 and 5V pins, the wiring is more flexible and diverse; 3.I2C SDA and SCL pins and the corresponding 5V and GND pins are provided for module connections such as LCD1602 LCD display for I2C communication more possibilities; 4.With on-board passive buzzer, connected via jumper cap; 5.Power supply method includes DC head and USB socket power supply. Parameter: PCB board thickness: 1.6mm Small round hole diameter: 3.0mm Large round hole diameter: 4.6mm (compatible with holes) Product Size: 57mm / 39mm / 15mm USB input voltage: 5V DC head input voltage: 6-12V Material: pcb colour: black Package Contents: 1 x Expansion Board 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. Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!