Starrett Magnetic Base Universal Indicator Holders with Triple-Jointed Arm &amp Fine-Adjustment (657-1)

Magnetic Base Universal Indicator Holders with Triple-Jointed Arm & Fine-AdjustmentCOMPLETE ASSEMBLIESThe working area is within a hemisphere having a radius of approximately 12" (300 mm)The very sensitive fine- adjustment is located on the magnetic base to eliminate indicator deflection when it is being adjustedModel 657-3 Universal Indicator Holder Arm Assembly can also be used on Model 659P Base using Model 659 Thread Adapter, Model PT18318Description: Universal Indicator Holder, No. 657W Fine-Adjustment, No. 657P Magnetic Base, No. PT17850 Indicator Holding Rod and No. 657S Snug