comments:
BaconThief2020 posted on r/askelectricians1w
That is the wire you want to run from the control box out to the loop. It's twisted so it won't set off the collar. You want a single wire going around the area you want to fence. A 500-ft roll of boundary wire is $17 at Walmart https://www.walmart.com/ip/PSUSA-500-Boundary-Wire-18-Gauge-Solid-Core/52141270