Thank you to Unique Master Models (UMM) for generously providing an excellent tool for “field testing.” Thank you as well to the IPMS Reviewer Corps for letting me be an evaluator.
The jig is akin to an adjustable protractor with a range of 0 to 180 degrees. The base plate is metallic blue metal with white, etched tick marks and numbers marked in 1 degree increments. A polished bar is screwed to the base plate at the zero position and an adjustable or positionable bar with a set screw can be locked between 0 and 180 degrees. Both plates are 3/16 in thick and project up from the base plate about 7/16 in. I checked the indicated angles on the jig with other tools and the angles match the precision of the jig, in other words, the angles on the jig are pretty darn good! The setscrew on the positionable plate held well and did not slip when the jig was dropped from about 5 feet onto a carpeted floor.