The A1331 is a battery model designed for the MacBook Pro 13-inch (Mid 2009 to Mid 2012), and it's specifically compatible with the MacBook Pro 13" Unibody series from those years (A1342).

Here are the details regarding the A1331 battery:

• Type: Li-ion rechargeable

• Voltage: 10.8V

• Capacity: 58Wh (watt-hours)

• Compatible Models:

  • MacBook Pro 13" Unibody (A1342)

  • **MacBook Pro 13" (Mid 2009, Mid 2010, Mid 2011, Mid 2012)

  
  

You can replace this battery if your MacBook is showing signs of battery degradation, such as quick draining or failure to charge. If you're considering a replacement, ensure the battery is from a reputable source to avoid issues related to counterfeit or low-quality batteries.

Let me know if you need any help with the installation process or other related inquiries!