Material: This engineering architectural drawing ruler is made of aluminum alloy material, don't worry about the ruler oxidize and rust FUNCTION: This woodworking stir gauge can accurately determine joint sizes without fussy measuring Application: Suite for many kinds of woodworking tools. Whether it is table saw, bevel saw, cantilever saw, push saw, engraving table or other tools for cutting slotsEasy use: Simply put one end of woodworking ruler into the gap, slide woodworking ruler to close the gap, then tighten knob to accurately read length of woodworking gauge gap, one gauge of seam saw, a depth gauge, woodworking. Ruler, depth measuring gauge Convenient: gaps gauge with high practicability, easy to use, flexible operation, carpenters enthusiasts, designers, engineers, architects, students, teachers deserve it