These numbers are Plantronics’ date codes. Here’s an example:
The 11-05 is simply a month and year of manufacture, in this case 11/05 or November 2005.
The H is for H series (or P for Polaris)
The number is indicative of the model:
Enc. Bin. 10
SupraPlu Bin 26
SupraPlus Bin 36
So the number in this case indicates that this is an Encore binaural
The NA means it is Noise Canceling.
You see, we can learn quite a bit from that date code! My mystery headset is an H101N!
Left -a diagram showing the location of datecodes on different headsets. Upper left - the .Astrogator with the complete datecode information.
The complete key for these codes is in the “attachments” field as an excel spreadsheet.
Headsets manufactured by Plantronics before 1995 have a bit different coding procedure,
which is also in the excel spreadsheet.