Casio SP2-R Sustain Pedal This optional sustain pedal will enhance your keyboard experience A critical accessory for keyboard players The pdeal works with the following models: CPS-7, CPS-85, CTK-481, CTK-491, CTK-495, CTK-531 Also with CTK-541, CTK-591, CTK-611, CTK-620L, CTK-631, CTK-691, CTK-731, LK-55, LK-73 WK-1300, WK-1350, WK-1630, WK-3000 and WK-3500.