The Rope Logic Whoopie is a time-tested design that allows workers to mount hardware snugly against a tree in seconds. Whoopie slings adjust by sliding the tail through the hand-spliced center section and are locked into position by stretching the center section out along the tail. These slings are made with the industry-standard Samson Tenex-Tec line, but are also available with the new Tenex-Tec Pro line. Samson Tenex-Tec Pro is more durable, solution dyed, has an arborist-specific construction including a custom twist rate and a roughly 20% increase in strength across all sizes. Cordura abrasion-resistant sleeve on each eye for increased lifespan. Quickly attach your rigging gear without slack. Hand-made by the experts at Rope Logic and rigorously tested in accordance with a 3-Sigma Process which provides a much more accurate MBS rating than standard testing processes.