I see SOS as a slow blinking strobe mode....and it's good to have it...I need it for road emergency.....I really like my HDS 60 flash(strobe) mode......1/10 of a second in interval of 1 second...As I said it before I need a flashlight with well overdriven strobe mode..Something like a camera...
HiltiHome is right.
MKII with the new body is 1.5mm longer.
I'm posting the same pic but upside down.
See ruler in lower left corner.
MKI-90.5mm , MKII 92mm.
each blue square = 1mm
Edit:
MKII's tail cap on the picture is not fully tighten.
The body is probably just 1mm longer.
I'm still...
Out of six tests , only in 2 the MKII fell into blinking mode(battery=0.9v.)
Obviously this is not a feature, but I do not have any explanation.
Anyway when NiMh drop to 0.9v the flashlight is very dim, as dim as the lowest setting of my HDS U60 – 0.08 Lumens
there is more to investigate...