The EXFO OTDR Priority Calibration and Verification option (Millennium part 524862) moves an OTDR to the front of EXFO's service queue for calibration and verification, cutting the turnaround time a fiber test crew is without their unit. It's a service add-on rather than a physical part, aimed at operations that can't afford extended downtime on a primary OTDR during a build schedule. Adding it when you send a unit in for annual calibration keeps test crews equipped and compliant with measurement standards. Pair it with EXFO's OTDR service kits for ongoing equipment maintenance.