ChugPlug External Battery Pack for MacBook Air 11" and 13" and MacBook Pro 13" Portable Charger (Works with 60 and 45 Watt MagSafe Adapters) 11" MacBook Air: up to 4 Additional Hours 13" MacBook Air: up to 3 Additional Hours 13" MacBook Pro: up to 3 Additional Hours (will not charge MacBook Pro 15) Proprietary Technology with International Patents Pending Seamlessly Integrated Design: Utilizes your original Apple AC Power Cord & MagSafe Power Adapter 2 hour charge time to fully recharge the ChugPlug External Battery Pack Works with 45 Watt and 60 Watt MacBook (will not function with an 85 Watt Adapter) 1 Year Warranty