This keypad has 16 buttons arranged in a telephone-line 4×4 grid. It’s made of plastic with sturdy buttons. The keys are connected to a matrix, so you only need 7 microcontroller pins (4 columns and 4 rows) to scan through the pad. It’s basically a sturdier version of our Membrane 3×4 Matrix Keypad and comes with 7 or 8 header pins pre-soldered on for easy plugging. Starting from the left, there are three column pins, and to the right are the four row pins. If yours has an 8th pin, it’s not used, and you can just leave it disconnected.

• Standard Header Pin Connector
• Tactile type switches
• Over 1,000,000 operations per key
• Dimensions: 56mm Wide, 80mm High, 17mm Thickness