This Matrix Keypad 4 X 3 has 12 buttons, arranged in a telephone-line 3x4 grid. The keys are connected into a matrix,hence only 7 microcontroller pins (3-columns and 4-rows) are required to scan the pad.
Can be attached on any surface
Only 7 microcontroller pins are needed to access 12 buttons
Size: 70mm x 77mm x 1mm