Difference between scubapro mk16 vs mk17

[Techguy]

Hi I am having Little trouble getting info to tell the difference between the MK16 and MK17 any thoughts.
Thanks

 

[halocline]

The MK16 is not environmentally sealed, and originally had a different seat. There was an upgrade to the MK17 seat that I believe was automatically included in an annual service, so any MK16 that's been serviced recently should have the new seat.

Other than the environmental seal, I believe there is almost no difference.