You would think they were everywhere, but I tried half a dozen stores before finally finding them there.
I connected the 16 ga wire to the end of the pen with one of the terminal connectors, clipping the other end about even with the thru hole. I used the 18 ga. wire (bent at 90 degrees) up thru the deck into the throwbar. I did have to enlarge the throwbar hole with a 1/16" bit. Connect the 2 wires together with another terminal connector leaving some overlap for adjustment.
Give the Goop 24 hours to dry before adjusting the wire.