Subaru 1998 Impreza Owner's Manual page 287

Horizontal beam
angle gauge
Vertical beam angle gauge
Bubble
1. Look at the vertical beam angle gauge. The bubble on the gauge
should not deviate from the center of the gauge by more than four seg-
ments on either side of the gauge.
Horizontal beam angle gauge
Red line
10-54
Vertical beam
angle gauge
OM-H0240
Center
mark
Acceptable
OM-H0379
Inner
scale
Red line
Acceptable
OM-H0380
Acceptable
Red line Red line
Acceptable
HG0179
HG0180