A millimeter-wave, high GAMMA on-wafer load pull system uses a tuner with extended inclined slabline (bend-line) and a manually controlled low profile pre-matching module, mounted on the bent section of the slabline next to the wafer-probe. The pre-matching module uses a mobile sliding rack and a rotating tuning probe; the rack is mounted on the slabline extension and controlled by a fixed pinion.Both the rack and tuning probe position and immersion into the slabline are controlled using sidewise mounted easily accessible manual knobs. The low profile of the pre-matching module is a crucial feature and allows integration on the extended slabline of the tuner in immediate proximity of the wafer-probe, thus minimizing any additional insertion loss and maximizing tuning range. Manual handling of the pre-matching tuning module is easy and a pre-calibration allows efficient on-wafer load pull operations.