Welcome to our store! 1. These are fantastic keyboard modules used for single-board microcontrollers. 2. 4*4 button design, a total of 16 buttons on one keyboard module. 3. Small size, saves space, convenient to use and connect. 4. This is an excellent choice for external keyboards for microcontrollers. 5. Four mounting holes at each corner. Features: 1. These are fantastic keyboard modules used for single-board microcontrollers. 2. 4*4 button design, a total of 16 buttons on one keyboard module. 3. Small size, saves space, convenient to use and connect. 4. This is an excellent choice for external keyboards for microcontrollers. 6. Four mounting holes at each corner. Specification: Button: 16 Material: ABS Color: shown as picture Package list: 1 * Keyboard Satisfaction Guarantee: Customers are our top priority. If you find any problem with the product, please contact the seller immediately. We strive to provide satisfactory customer service.