From visiting their site, Treehopper offers the OCB in three different formats. Just the OCB buckle, the a strap sewn to the D-ring, and with a "safety J" that can be clipped to the D-ring so the strap doesn't have to be retreaded each time. I have some steps and have considered getting one of these to try a ROS......but I would for sure get the 3rd option so once it is set up, I don't have to fiddle with it in a tree. On a different SH thread of the same basic theme, I saw a video and diagram where the OCB was thread correctly.