If you need a replacement or want to built a custom Bungee Brake, grab exactly the amount of Bungee Cord you need. Lengths under 100' come with each end knotted, which reduces the total length by apx. 3 FT. FEATURES 1/2" Heavy-Duty Bungee 20 FT BUNGEE BRAKE KIT For zip lines up to 200 FT long. 30 FT BUNGEE BRAKE KIT For zip lines between 200-500 FT long. DOUBLE 30 FT BUNGEE BRAKE SYSTEM Includes two lengths of bungee cord. Used for special situations where more braking force is needed. Use the Bungee Cord with a Brake Block. Lengths under 100' come with each end knotted, which reduces the total length by apx. 3 FT. Bungee Cord will stretch, but must never exceed 175% of original length For example: 20 FT Bungee minus 3 FT = 17 FT X 1.75 = 29.5 FT. 30 FT Bungee minus 3 FT = 27 FT X 1.75 = 47 FT. If you need custom lengths of bungee cord, please make sure you notate the required lengths in the "Order Special Instructions" box in your shopping cart. Make sure your notes are there when you proceed to payment. Notes will automatically delete if you navigate out of the shopping cart to continue shopping.