electric power: 45W; Input: AC 100-240v-1.5a, 50-60Hz; output: DC 14.5V-3.1a 45W AC adapters manufactured with the highest quality materials, tested Units, Safety: CE-/FCC-/RoHS-Certified for safety, include laptop safeguard features against incorrect voltage, short circuit, internal overheating.An amber light lets you know that your notebook is charging while a green light tells you that you have a full charge. Fully compatible:Compatible with MacBook air(13 inch, Mid 2011), Compatible with MacBook air(11 inch, Mid 2011), Compatible with MacBook air(13 inch, Late 2010), Compatible with MacBook air(11 inch, Late 2010), Compatible with MacBook air(13 inch Mid 2009), Compatible with MacBook air(13 inch, Late 2008), Compatible with MacBook air(13 inch, early 2008). part Number: A1237 A1244 A1304 A1369 A1370 A1374 Durable material: made of highest material that can against over current, over voltage, over load, short- circuit protection and auto recovery. Certificated with UL/CE/FCC/RoH