Security System Keypad.

The 4×4 Matrix Membrane Keypad is a lightweight and versatile input device available at RoboShop BD. Arranged in a 4-row by 4-column grid, it provides 16 unique keys (0–9, A–D, *, #) while only requiring 8 microcontroller pins. Its paper-thin, flexible construction and convenient peel-and-stick adhesive backing make it incredibly easy to mount onto any flat surface, project box, or control panel.