Difference between a HT1250 connector and a GP388 connector?

[Brandon_K]

We're looking to pick up some decent quality, noise cancelling headsets. In my searching, I came across a few nice units for a great price, but they're listed for a GP388. The manufacture says it uses a M3 connector, where the HT1250 uses an M2. I've compared the pinout's, HT1250 here and GP388 here. Both use the same 6 pins (1, 2, 4, 5, 6 and 7) and those pins all have the same functions listed.

Is there a physical difference between the two connectors? From pictures, they look identical. Comparing audio adapters (to adapt to the 2 pin M1 connector), they too look identical, but I don't physically have them to compare against.

Thoughts?