ChrisNik True Plumb Rod Calibration Tool The ChrisNik True Plumb is a precision calibration tool designed to quickly check and adjust prism poles and GPS rover rods . This quality-control device allows surveyors to verify rod plumb and bubble accuracy in seconds, helping ensure reliable measurements in the field. Compatible with most prism poles and fixed-height GPS rods, the True Plumb provides a simple and repeatable method for maintaining properly adjusted survey equipment. Key Features • Tests and adjusts prism pole bubbles and rod plumb • Compatible with most prism poles and fixed-height GPS rods • Allows 360° rotation to verify rod alignment • Durable steel construction for long-term use • Essential quality-control tool for survey crews Ideal For Surveyors and field technicians performing routine prism pole calibration, rover rod verification, and survey equipment quality control .