1 It can be used in night. 2 it is easy to bring 3 it can measure direction,obliquity,gradient,upright,milemeter horizontal. picture 2 picture 3 picture 4 picture 5picture 6 1 The compass can measure direction,obliquity,gradient,upright,milemeter,horizontal. Used in geology perambulation, colliery and other mine exploitation military training.2 specificationMain ...