#PetzlTips - Tying a Prusik Loop for a Rappel Backup Rappelling is an important skill for all climbers. Do you have accessory cord on-hand to make a Prusik for a rappel backup? Here's a tip to make sure you’re prepared. You’ll need 1.5 meters of 6mm cord. There should be a sufficient difference in diameter between the Prusik and your rappel rope. If you're learning a new skill or have any doubts, you should always seek instruction from a qualified professional. #prusik #climbing #petzl | Petzl