[Steve]

I just happen to have a h601 arnie on my desk awaiting a new battery. Here are some shots of the crown and stem.

 

[Steve]

I don't have a good micro measurement tool, but I'll do my best to give some measurements.

Crown: 5mm
Length from the bottom of the crown to the tip: 17.5mm
Length of the 2nd skinniest part of the stem to the tip: 15mm

 

[Steve]

The end has a small gear that I believe changes moves the minute hand.

 

[Steve]