Sterling Rope Sr Mdp Mini Double Pulley Mbs 22 Kn Up To 11mm 1.1″ Sheave Black The Sr Mdp Is A Lightweight Aluminum Double Pulley That Can Accommodate 2 Ropes Up To 11mm Each. This Pulley Can Be Used To Set Up A Haul System Or To Tension A Line. The Curved Side Plates Are Designed To Allow The Pulley To Tend A Prusik To Capture The Progress Of A Rope Being Hauled Through The Device.