Difference between MK2 and MK2 Plus

[UaVaj]

like to know the (1) gas delivery performance difference at depth and (2) physical difference as how to tell them apart
and
(3) be a bonus to know the internal difference.

 

[SCUBAPRO Harry]

The MK2 has had many faces since its inception in 1963. It went to a modified version called a MK200, then back to a MK2, then eventually, todays version the MK2+.
The 1993 MK2 followed the last MK200 and had 3 LP ports.
The 1996 MK2 followed that with 4 LP ports.
The !998 MK2+ was introduced by adding a coldwater coating to the IP spring, awarding it the '300 bar cold water EN-250 certificate. Since then, the reg has remained functionally the same with cosmetics changes.