Fowler Economy Indicator Stand Features Include... Accepts all lug-back indicators Positive lock screw Column is 5/8" from back edge of working surface. Column diameter: 1" Fine adjustment: 3/8" Capacity of 6-1/2" from working surface. Bracket with 1/4" bolt for dial indicator is 2-1/4" from center of column. Fine adjustment knob for zero setting. Rapid preliminary positioning adjustment is featured. Ground steel post mounted at right angles to the base. Ground working surface 5-1/2" x 4-1/4"