Define your board

If you see

Serial code start from A, 

Brought from 2020 - 2021,

with Battery lid 

Your keyboard is 

Series 2020 - 2021

Compatibility with

DKOS 2 (Stop update)

If you see

Serial code start from B, 

Brought from 2022 - 2024,

No Battery lid and chargerable

Your keyboard is 

Series 2022 - 2024

Compatibility with

DKOS 3 (Stop update)

DKOS 3.1 (Coming soon)

If you see

Serial code start from C, 

Brought from 2025,

No Battery lid and chargerable

Your keyboard is 

Series 2025

Compatibility with

DKOS 4