It's not just a question of connectors as stated in the previous comment but of optimisation:

"The entire Evole range is available in 2 versions: "UC" models for "unified communications" and "MS" models for Skype for Business. There is no difference between these versions in terms of audio, finish, features or accessories.

The only difference is that the references followed by the initials MS offer immediate call control compatibility with the Skype for Business VOIP communications system.

The 40 MS connects via a USB socket, the 40 UC connects via a USB-C socket.