When you purchase a hammock, the package commonly includes the accessories as well. Hanging kit is a regular accessory needed for hammock installation. Double hammock by Grand Trunk also includes W20 hanging kit accessory in the package. This hanging kit consists of metal carabineers and cord. The installation procedure requires you to connect hammock and trees (or other steady spot). The cord is used to make a strong knot with carabineer at the other end of the knot. The carabineer is connected to each end of the hammock. Hammock is commonly using triple stitch seam on both ends. It allows you to attach carabineer easily.