Almost every Arduino project I can think of needs some sort of inputs. It can be as simple as a button, or more complex like a motion sensor, but odds are you’re going to need a way to interface with the project.
This 9-button keypad offers large and durable 12mm buttons and the ability to connect it using only two pins (Analog input and GND). The kit comes with the keypad PCB, 9 12mm SMD buttons,and 9 10K 0603 SMD resistors.
Two versions are available: one that you need to solder, and one that is ready to use. You can also find example Arduino code on Github. The video below shows the keypad in action.
