Hi Steve,
The rev 2 is the accurate one. Here's some test results:
Morandir test results on the
18350 - RMS on watts
Morandir test results on the
18650 - RMS on watts
Stefan's test results on
volts and watts. Use Google translate on this one.
Solemn Penguin on the
variable voltage. Compares Zmax version 2 against Zmax version 1, Provari, and the Varitox.
I believe Mad Vapes are calling it the rev 2.
ETA: The version 1 menu goes to 7.
The version 2 menu goes to 8. If you see a Zmax advertised with an 8th menu for RMS it's a version 2.