Ortlieb QL2 Lock

"The QL2 Lock from Ortlieb is the ideal bike bag lock for all cyclists who want to keep their valuables safe on the go. Specially developed for securing QL2/2.1/2.2 bicycle bags to the luggage carrier, this lock can be installed without tools and thus offers a quick and uncomplicated way to secure your bag. With a simple key mechanism, the lock can be easily closed and opened, making it a practical companion for everyday use."
"Thanks to its compatibility up to a tube diameter of 16 mm, the QL2 Lock is versatile and fits most luggage carriers. In addition, it can also be used in combination with the E124/E125 models as additional protection against quick access to the contents of a rollerbag or to secure the helmet. Whether you are commuting to work or going on a bike ride, this lock provides the necessary security for your equipment."
"The unisex design of the lock fits every bike and is specially tailored to the needs of cyclists. With the QL2 Lock from Ortlieb, you are ideally equipped to securely and reliably fasten your pannier so that you can concentrate fully on your ride."