NEW Spring Stop - Don't Get Slammed! This ZLP exclusive Spring Stop will give you that extra cushion you need to stay away from that tree. Made from stainless steel, and with our heavy duty recycled plastic ends that are secure with clamps for major durability. The Spring Stop is made for the zip lines 100' or less with 6% grade or less. The kids (adults too) will love the extra length you get out of your shorter zip line runs, as opposed to using a standard bungee braking system. Just feed the cable through the black plastic ends and send down to the end of your zip line. The trolley will bump into the Spring Stop and the spring will compress and slow down the rider. If your zip line is already set-up, you will need to remove the cable to install this product. 3' Long 1 1/4" diameter fits cable up to 1/2".