RM-1104 vs RM-1085 Lumia 950

[Windows Central Question]

As Microsoft is on back order for the Lumia 950, I'm tempted to purchase the phone on Ebay. Can anyone tell me if there is any difference between the two RM types? Are either of them dual sim or do I need to purchase from Microsoft in order to get the dual sim version?

 

[TheChazas]

Unlocked and ATT?

 

[s n1]

firmware version
Lumia 950 RM-1104_15430
Lumia 950 XL RM-1085
Lumia 950 XL Dual SIM RM-1116

Microsoft Publishes List Of Lumia 950 And Lumia 950 XL Variants That Will Receive New Firmware Update - MSPoweruser