4X Marine Ruler Parallel Ruler Nautical Charts Parallel Ruler Mapping Points to Pull Parallel Ruler 450MM

The main role: Before Chartwork for drawing lines bearing line or course, the degree or amount of bearing line degree course line.
Two hands each holding a ruler of David, alternately moved in parallel.
Usage: When the move operation, the appropriate force to suppress static hand -foot, one hand pushing moving feet, two feet alternately moved in parallel until the required position. Alternately moving, to prevent the static foot displacement.

size:450mm
Material:plastic
colour:White

Package Contents:
4 * Chart parallel ruler

Only the above package content, other products are not included.
Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.