Three Axis Articulated Arm with HI-mass Base (PPM203B) Multi-turn Fine Adjustment Controls for All Three Axes (PPM203B) Fully Flexible “Gooseneck” Arm for Different Positions (Locks Securely in Place with Adjustment Control Knob) (PPM100) Fine Adjustment Knob on Probe Holder (PPM100) Spring Compliance in Probe Holder Keeps Pressure at the Probe Point (PPM100) Heavy Base for Desktop Applications or C-clamp for Other (Rack) Applications, Both Included (PPM100) Adaptable to Most Tektronix Probe Types