This is a 12 button matrix keypad with a 8 pin, 2.54mm pin header. The first 4 pins of the pin header are the rows, and the second 3 pins the columns.
Simple matrix keypad decoder software can be used to decode key presses. For example this arduino code. Google "matrix keypad decoder software" for heaps more.
This keypad can be connected to the Modtronix LCD2S range of serial LCD displays with keypad decoders. A standard 8 pin, 2.54mm female cable can be used to connect to the pin header of this keyboard.
1 x Keypad