Difference between CarPlay Upgrade Hub SKU numbers?

[Rdecker]

I am looking to purchase the OEM Mazda CarPlay upgrade hub for my 2017 CX-9. I can anybody explain the difference, if any, between these different hub sku numbers below. The numbers are the same except for the last digit.

TK78-66-9U0E
TK78-66-9U0C
TK78-66-9U0D

Thanks

 

[rowlands57]

Usually a different last digit represents an update to the prior version. In the case above the "E" would be the latest update to the hub.