But if you use the magnetic trailer lights from Harbor Freight, which are always on sale for $9.99, just save you some time and throw them away now. Upgrade to their $20plus magnetic light kit. The cheap ones always fell off on me. The upgraded ones have much better magnets and take the bumps better. Never had any trouble with them. I always tape them down too with some good quality duct tape, just in case. If they're not hard to pull off, they will come off.