"Your trailer hitch hand grenade is prohibited from both carry-on and checked bags. So what’s the big deal if it’s inert? First off, we don’t know it’s inert until explosives professionals take a closer look, and that takes time and slows down the line. It can even lead to a complete shutdown and evacuation. Also, imagine the person sitting next to you on the plane pulling this out of their carry-on. For these reasons, anything resembling a bomb or grenade is prohibited from both carry-on and checked bags. #TSATravelTips This inert grenade was discovered in a checked bag recently at the SBP airport."