The AB100 uses a non standard six pin XLR connector for the headset. This connector will accept a standard 5 pin XLR but not the six. The part numbers for XLR connectors that will fit are:
SwitchCraft A6M
Neutrik NC6MSX  (or NC6MSXX) do fit Clear-Com products 
The Neutrik® Model # NC6MX does not fit.
The text of the documentation from the Neutrik® web site says:
"Why does my 6-pin XLR not fit into the AB100 6-pin XLR?
Currently there are two configurations of conventional 6 pin XLRs. The NEUTRIK 6 pin XLR meets the industry standard according IEC 61076-2-103. Nevertheless NEUTRIK offers both types of 6 pin configurations. The standard NEUTRIK 6 pin has black insert - the insert of the non-standard configuration is gray.
The difference in the part #s is the addition of an “S” – for example:
Standard 6 pin male XLR cable connector –nickel housing/silver contacts = NC6MX
Same part with non-standard pin configuration = NC6MSX"