LB1 High Performance Battery for Apple 661-5229 [2009 2010 2011 2012] Macbook Pro Unibody 13 inch MB991LL/A Battery Type: Li-Polymer; Capacity: 5500mAh/60.5Wh; Cells: 6; Voltage: 10.5 V Premium Grade A cells ensures peak performance and reliability. Operation time depends on the capacity of the battery, laptop settings, power consumption of equipment, and how you use it. CE-/RoHS-/FCC- Certified and Built-in circuit protection ensure both safety and stability. Live Support Mon-Fri 4am-8pm PST | Sat-Sun 8am-5pm PST | 18 Months Hassle-Free Warranty. Compatible with: Apple 661-5229 [2009 2010 2011 2012] Macbook Pro Unibody 13 inch MB991LL/A