9V AC/DC Power Supply Adapter 500Ma (0.5 Amps) 5.5 Mm*2.1 Mm Tip (5.5Mm OD X 2.1Mm ID) - AC To DC Electric Transformer Inverter For 9-Volt DC Electronic Devices Under 0.5A Slim Wall Plug & RED LED UL

UL 60950-1 Certified & ROHS Compliant - Standard DC Barrel Jack:5.5mm x 2.1mm (5.5*2.1mm) - Top Positive (+) Polarity (Center Connector Positive outside Negative) - Be sure to verify your device requires a 5.5mm x 2.1mm DC Barrel Jack & Center Positive Polarity - Not for Musical Devices or Any Other Requiring Center Negative Polarity