Alpha® Classic AK and Alpha® Hybrid AK Liners Sizing Guide Please refer to the below charts for recommendations for fitting both Alpha Classic AK Liners and Alpha Hybrid AK Liners. Shown below are limb circumferences that the various liners will fit, measured at 4 cm (1.5 in) and 30 cm (12 in) from the distal end. Prefabricated transfemoral Alpha Liners are only available in Medium Plus, Large, Large Plus, and Extra Large sizes. NOTE: Accordion distal umbrella sizes change with each size liner with symmetrical profile. Medium Plus Proximal Measurement Distal Measurement Large Plus Extra Large Proximal Measurement Distal Measurement 4 cm (1.5 in) from distal Medium Plus Large Plus Extra Large