Wireless System Discovery 600 Series Bluetooth Headset (610, 640, 640E, 645, 655 and 665) 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 I05 on your wireless product, I is the month of September and the 05 is the year 2005.
The three character Date Code is located on the same side of the headset as the eartip. It appears at the end of the final row of text. The first character is a letter and the final two characters are numbers (for example, E05).