Hikvision ip camera models differences

[Janis B 0]

Hi team!

I have question regard Hikvision ip cameras models difference. For example DS-2CD2T86G2-2I/4I.
https://www.hikvision.com/en/products/IP-Products/Network-Cameras/Pro-Series-EasyIP-/ds-2cd2t86g2-2i-4i/

What is a differnece between DS-2CD2T86G2-4I(2.8mm), DS-2CD2T86G2-4I(2.8mm)(C), DS-2CD2T86G2-4I(2.8mm)(D) models ? 

I can't find any information.