Review on Precision Stainless Woodworking Protractor for Accurate Degree Measurement by Andrew Cramer

This product is well made and the scale is accurate. When used correctly, angle measurement accuracy of up to 1/4 degree is possible. I gave the product 4 stars because the screw is either loose or over tightened and seizing when adjusting the blades. The blades are mounted with a shoulder screw and compression washer. For proper operation, the support shoulder must drop before the blades lock, and the compression washer provides enough friction to hold the blades in place, but they can be adjusted. The problem is that the compression washer that comes with it is too thick and stiff to allow the bolt to rest against the bead. Instead it rests on a thick washer and blocks the blades. A thinner compression washer from your local hardware store should fix the problem.