Angle Finder, Mag, 0-90 Deg, 4 1/2 Base/ GENERAL CHARACTERISTICS ITEM DESCRIPTION: MAGNETIC BASE; V-GROOVED SIDE; HIGH IMPACT PLASTIC HOUSING; 4 IN. DIA DIAL; 1 LEVEL VIAL; NOTCHED BACK; FOR READING ANGLES 0 TO 90 DEG; ACCURATE TO 1/2 OF 1 DEG; ANGLE AND GRADE CHART ON BACK SHOWS ANGLES IN DEGREES AND CONVERTS THEM TO PITCH PER INCH AND PITCH PER FOOT; 4-1/2 IN. BASE LENGTH