HFS (Tm) Magnetic Base Indicator Back holder For AGD2 1" Dial Indicator Go to amazon.com Related posts Check expert advices for indicator base? FeatureSize: 2-1/4"Diameter 9/16"Attaches to the back of a 1" dial indicatorMagnet screws offPowerful Magnet DescriptionMagnetic Indicator Back For AGD2 1" Dial Indicator Indicator NOT Included