Years of development, testing and fine tuning has made CMC's Prusik cord a preferred choice by rescue schools, agencies and rescuers alike. CMC sewn Prusiks offer unmatched performance — with strength equivalent to a tied Prusik loop, just without the cumbersome knot. The factory-sewn SecureStitch^TM is covered with durable clear shrink tubing that allows regular inspection and helps protect the stitching for longer life. Some rescuers prefer a bound-loop style Prusik for cinching the attachment bight around the carabiner to help snug the Prusik to the connector. CMC's AZ Bound-Loop Prusiks are identical to our Sewn Loop Prusiks except that the shrink tube captures both sides of the loop while allowing adjustment.