Expanding Rubber Transom Drain Bung with 6mm S/S nut & bolt to fit 22mm ID tube

A boat transom rubber bung is a type of drain plug used in boats to allow water to drain out of the transom. It typically features an expanding mechanism that fits into a hole in the transom, ensuring that water can escape even when the boat is on its trailer or in storage. This prevents water from accumulating and potential damage to the engine or other components.