1 combining the principles of the surveyor's compass, prismatic compass, clinometer, hand level, and plumb. When the compass is unfolded, it produces two sights with peepholes. You have the option to sight through a clear window in the lid or lay the lid completely open and use the second hinged peep sight. The interior of the cover features a mirror with a vertical line inscribed.

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

Precision of long air level :20' ± 5'/2mm

Precision of circle air level:30' ± 5'/2mm

Reading error:≤0.5°

Dial scale: 1°

Weight:0.24 kg

Size:80 × 70 × 35mm