Properties:

A device designed in the form of a slide rule, having one or more scales of varying ranges, on either surface, and a plastic cursor with a matte to receive pencil markings of range correction. It is used with various types of ground and sky-sweeper weapons to determine quadrant elevation, angle of sight, or drift, and to calculate the trajectory of a projectile in relation to a target. It may contain scales for yards to meters conversion and gage points which are used in conjunction with the cursor and range scale to convert data given in meters to yards. Scales may be in mils for determining high angle fire, time of flight, deflection shift, and the like.