@anon58673590 You may want to know the exact meaning of SN number:
For example:
Pimax 8K SN: 200004 8 29 00001
1.200004 is internal code
2. 8 the year(2018=8;2019=9)
3.29 this headset is produced in 29th week of 2018
4.00001 the Serial code of this headset in this week