Hitachi Zaxis 850LC-3 Operator's Manual page 136

Armrest Adjustment
Armrest (5) can be pulled upright by hand to get on and off
the machine easily.
The angle of armrest (5) can be adjusted to the desired posi-
tion by turning adjusting dial (6) located on the bottom of
armrest (5).
OPERATOR'S STATION
5
6
1-84
M1G6-01-017