3mm shock cord passes through the pen tube, through the line lock, I put a knot to stop it slipping through the line lock. It is tied to the hook ring and just has a reef knot and whipping to close the loop. I was going to use some mini carabiners and 3mm polyprop to guy out. With the carbon tubes, when they arrive, I plan to use some 0.8mm polyester cord I have and pass this through the tube, sewing it into the tape top and bottom, much closer in. Then I'll have a separate piece of 3mm braided polyprop to guy each out, using the line lock as it was designed to be used. I'm going to experiment with a bit of shock cord from a loop in the guy to the plastic hook. I'll post something once I have it right. .