Crescent Lufkin Red End Series T656N Rule, SAE Graduation, Wood, White/Yellow

Used by bricklayers for spacing brick courses. Spacing range 2-7/8 to 3-1/2 in and in 1/16 ths increments. Brick spacings identified by black letters A-K. Rule is printed in yellow. Regular outside markings in black. Brick Masons scale on inside, red course counter numbered consecutively.