UPBRIGHT DC 9V Adapter For Casio CTK-700 CTK-800 CTK-900 CTK-2000 CTK-2100 CTK700 CTK800 CTK900 CTK2000 CTK2100 Piano Keyboard World Wide Use Power Supply Cord Cable Charger - Walmart.com
Casio CTK-900 re-edited because it's just such a classic :) - YouTube