Datalogic Matrix 320 Product Reference Manual page 72

INSTALLATION
3. Tighten two silver screws and two silver washers into the aligned holes to secure
NOTE
58
MATRIX 320
the position. Finally tighten the central screw.
The particular distribution of the holes on the two brackets allows easy
adjustment of the skew angle in steps of 15°.
Figure 41 - Skew angle adjustment