Multiple keys let us keep one with each traveller and another in a separate pouch. Nobody had to wait for one shared key at the hotel.

Solid brass offers better rust resistance than the plain metal locks I replaced. I still dry them after a wet station transfer.

One compact lock now stays on my gym bag for the change-room locker. The key turns cleanly without forcing the small mechanism.

Before packing, coloured tags went onto the four keys and matching locks. That stopped us trying every key on similar brass bodies.

Across two suitcases and two backpacks, four 20mm brass locks covered our family luggage. Their small size passes through the zipper pulls without hanging too low.