Description: Our Brainiac Whoopie Sling is fully adjustable and designed especially for use with port-a-wraps and other anchoring devices for tree rigging. Create Girth Hitches and choke points on trees without carabiners or other connecting links. The Brainiac Whoopie is perfect for lowering wood, limbs, and branches. The small eye is used to girth hitch the portawrap while the other eye is used to adjust the length in mere seconds.