Ortlieb QL2-Lock

"Because you love your ORTLIEB bags, we have developed a reliable lock for the luggage carrier to protect them from unintentional removal. The specially developed lock is suitable for all Quick-Lock 2 systems. The lock is compatible with all standard luggage carriers up to 16 mm tube diameter and remains open after unlocking so as not to interfere with the insertion and removal of your bag. It can be easily placed on your Quick-Lock system and mounted without tools. In addition, the anti-theft devices (E124/E125) for QL2.1 bags can be used as options to secure the roll closure or other items such as helmets. For even more convenience, the lock is also available as a keyed alike version with two identical keys."