Straps over tires to hold the towed vehicle on the dolly. Exact set up depends on the type of dolly you have. The ratchets are used to hold down and tighten the tie down straps netted over the tire to the dolly system. Very essential to the set up.
Joe a/k/a "Americanrascal"
2016 Winnebago Adventurer 38Q +tow dolly
8th RV to sit in our driveway in 40 years