FYI
My current understanding after research.
Tilt
V1 = dark green circuit board, 2 screw caps
V2 = black circuit board, longer battery life, 2 screw caps
V3 = only 1 screw cap
Ordered directly from Tilt and received V3.
https://www.youtube.com/watch?v=k54L6njMfmcNote: in video he says after changing battery, calibrate in water within 1 minute.