20V, 4.25Aが条件。
他のバージョンだと18Vだったり16Vだったりするので注意が必要。
http://www.amazon.com/MagSafe2-Power-Adapter-MacBook-display/dp/B00BIDYGPI/ref=sr_1_6?s=electronics&ie=UTF8&qid=1369033160&sr=1-6&keywords=ac+adapter+macbook+pro+20V
http://www.amazon.com/Magsafe-Adapter-Charger-Macbook-Md506ll/dp/B009SOUXVA/ref=sr_1_3?s=electronics&ie=UTF8&qid=1369033160&sr=1-3&keywords=ac+adapter+macbook+pro+20V
http://www.amazon.com/Replacement-MagSafe2-Adapter-MacBook-Warranty/dp/B00BIDDSR0/ref=sr_1_2?s=electronics&ie=UTF8&qid=1369033160&sr=1-2&keywords=ac+adapter+macbook+pro+20V
http://www.amazon.com/MagSafe2-Adapter-MacBook-MD506LL-display/dp/B008Y6FE62/ref=sr_1_5?s=electronics&ie=UTF8&qid=1369033160&sr=1-5&keywords=ac+adapter+macbook+pro+20V
