GTL’s calibration substrate and positioning solutions for precision microwave probing, highlighting the GTL Calibration Substrate 1022 with its range of 250–1000 microns, SOLT standards, and short/long thrus for calibration verification and AFR use, along with details of the GigaTest Positioner and its compatibility with GTL nose pieces, theta-rotatable mounts, backlash-free micro-positioning, and optional motorized variant. Key Points Dedicated Calibration Substrate 1022 for Dual Probes with 250–1000 micron pitch. Includes Short Open Load Through (SOLT) standards for calibration. Long thrus support calibration verification; short thrus aid 4-port AFR and non-insertable calibrations. GigaTest Positioner is designed for precision microwave probing. Compatible with GTL nose pieces and 3" or 4" hard mounts enabling theta rotation. MicroPositioner knobs provide true 1-to-1 movement with no backlash. Robust, rock-solid design ensures probes stay fixed unless moved. Optional Motorized MicroPositioner is available for automated positioning.