Plantronics M25/M55 Bluetooth Headset Date Code
The date code of your product designates its date of manufacture, and it can be used to establish your warranty period. The date code is generally listed with your product’s model and part number, although this is not always the case.
The chart below can assist with understanding the date code.
Example: If you see A2 on your product, the A is the month of January and the 2 is the year 2002.