ProLock Tree TieStrong and Multifunctional. Made of durable, high-density polyethylene, ProLock is stronger than most competitive chain lock products. ProLock simply pulls through itself and twists into a locking position. It’s also treated with UV inhibitors to prevent cracking or breaking down due to sun exposure. The carton offers efficient dispensing of just the length needed,saving time and materials. 1/2″ wide with 100′ per carton.