A 4x2 matrix keyboard module is a type of input device that consists of a 4x2 array of buttons or keys. When a button is pressed, it creates a unique combination of electrical connections within the matrix that can be read by a microcontroller or other electronic device. These types of modules are commonly used in projects such as DIY keyboards, musical instruments, and other types of control panels. They are typically small in size and easy to interface with a wide variety of microcontrollers and development boards.

This 4x2 matrix of tactile switches are perfect for adding a user-interface to your system at the lowers possible cost. Perfect for Arduino projects.

There are 8 buttons in total.