Seco Tribrach Adjusting Cylinder The Seco 2001-00 Tribrach Adjusting Cylinder is a precision tool used for calibrating and adjusting optical plummets on tribrachs. It provides a consistent reference for verifying plummet alignment with a vertical reference point, ensuring accurate centering over control points in the field. Key Features • Designed for adjusting optical plummets on tribrachs • Provides consistent reference for centering accuracy checks • Supports precise calibration and alignment verification • Compatible with standard tribrach systems • Durable design for repeated use