around here in the winter you will see signs stating that drag chains are required when the roads have snow and ice on them. drag chains are for the braking wheels of your TT. the chains will keep the TT from sliding into another lane of traffic and cause a serious wreck or pull you off the side of the mountain or road. hope that explains it for you. My drag chains I bought at yard sales. just know the size of your TT tires and wheels. most chains are marked still in boxes.