DeadBolt KingPin Lock

If you are referring to a standard ball coupler on a trailer, unless the state of your residence has an ordinance for required use of a lock/pin in the coupler, the sales rep is technically correct. Most if not all states have towing regulations that require safety chains and breakaway systems in the event a trailer detaches but no mention of couplers. Odds of a coupler working loose is low, but having a pin or lock like <a href=https://www.campingworld.com/1-2-span-coupler-lock>item# 20486</a> is a personal safety preference on the road and will also help deter theft. A small investment of a pin or lock for your coupler can avoid casualties on the road, but also protect your own investment in to your RV from damage and theft.

Unfortunately no since the king pin sits fully in the cup of tripod stabilizers. Some tripod stabilizers have some form of locking system available like models from Ultra-Fab which includes a padlock to lock the stabilizers.