In this video, Lancaster Archery TechXPert P.J. Reilly demonstrates how to tie a D-loop onto the string of a compound bow.The D-loop is attached to the bowstring, to provide both a nocking point for your arrow and a connection for your mechanical release.You hook your release to the loop before drawing the bow. By doing so, you protect the serving on your bowstring from the wear and tear caused by your release.Reilly gives a step-by-step explanation and demonstration of the D-loop tying process, which you can imitate at home, and describes the tools you can use to do the job.Below is an illustration of how to tie a D-loop.