Simply remove the old rubber strip and replace it with the new one, and you're ready to go. Remember, if you need multiple strips for a 61-key keyboard, you'll need to order 5 pieces. For CASIO CTK-1100 CTK-1300 CTK-2500 CTK-700 CTK-2400 CTK-720 LK-120 LK-130 LK-100 Key ...