Looks like a low density wood ( soft fast growing plantation like pine, balsa or such light wood) block that is cut using a CNC or a milling machine to leave a 1mm or so recess for the LED displays on it. Then the buttons are most likely done using a thin ( 2mm or less ) recess and having capacitive switches on a PCB there, or by making it 1mm and mounting the switches in a recess that allow just pressing on the thin wood to operate them.