To measure direction, obliquity, gradient, upright, milemeter, horizontal. Used in geology perambulation, colliery and other mine exploitation military training.

Pocket Compass Model DQY-1

Precision long air level 15'±3'/2mm
precision of circle air level 30'±5'/2mm
The reading error ≤0.5°
Dial scale 1°
Weight 0.26kg
Size 85×73×35(mm)