OMNIHIL AC/DC Power Adapter Compatible with Casio CTK 533 CTK 540 CTK 541 CTK 551 Keyboard Switching Cable PS Adapter Rating: World Wide 100V ~ 240V 50/60Hz All products are tested to exceed/meet standard specification OVP, OCP, SCP Protection (OVP: Over Voltage output Protection. OCP: Over Current output Protection. SCP: Short Circuit output Protection) FREE RETURN SHIPPING / 5 YEAR FREE WARRANTY