AZ-Delivery Matrix Array 4 x 4 membrane switch 16 key keypad The keypad has 16 keys arranged in a 4x4 grid for phone lines. These keypads are made of a thin, flexible membrane material with a self-adhesive backing (just remove the paper) so you can attach them to almost anything. AZ-Delivery Matrix Array 4 x 4 membrane switch 16 key keypad keypad has 8 wires running from the bottom of the keypad, the wires are connected in order from left to right and connected to digital pin 2-9. AZ-Delivery Matrix Array 4 x 4 Membrane Switch 16 Keys Keyboard is great for various projects and applications, for example, security systems or data entry for embedded systems. https://elecena.pl/product/20614708/4x4-matrix-array-keypad-keyboard-compatible-with-arduino-and-raspberry-pi 2022-03-25 https://elecena.pl/product/20614708/4x4-matrix-array-keypad-keyboard-compatible-with-arduino-and-raspberry-pi 2022-10-25 https://elecena.pl/product/20614708/4x4-matrix-array-keypad-keyboard-compatible-with-arduino-and-raspberry-pi 2023-10-30 https://elecena.pl/product/20614708/4x4-matrix-array-keypad-keyboard-compatible-with-arduino-and-raspberry-pi 2024-08-05