Accessory USA AC Adapter for Boss Dr. Rhythm DR-3 DR-5 DR-550/550 MKII-MK2 Power Supply Products trademarked Accessory USA are marketed and sold exclusively by Accessory USA Store. Warranty:30 days Money Back Promised/60 Days Free Exchange With Paid Return Label/365 Days Anytime Worry-Free Warranty!**100% MONEY BACK GUARANTEE !! IF OUR PRODUCT CAN NOT WORK WELL** Output : 9V 1A