General Tools & Instruments 823 10-inch Digital Angle Finder Rule
This angle finder combines the ruggedness of analog rulers, both standard and metric, together with the digital technology needed for complete accuracy when measuring inside, outside and reverse angles.  Precise measurements prevent waste by facilitating exact miter cuts.  One button activates the reverse angle function, a hold button digitally saves the measurement and the large ergonomic locking know saves the angle manually.  A big LCD readout makes measurements extremely easy to read while an innovative center CHECK notch enables exact ruler placement marking.  This angle finder is ideal for framing, custom furniture building, stair and patio construction. flooring, tiling  and many woodworking, carpentry and contractor needs in the shop and in the field.