Some listings come with a factory-preset three-digit code while others are user-resettable so you can choose your own three-digit combination. Product pages will usually note whether a lock is 'preset' or 'resettable'—check the item details before buying.
These locks are sold as single units, two-packs, and multi-packs (for example 4-packs), so you can buy one lock or multiple locks in the same listing.
The main categories are TSA-approved luggage locks, indoor padlocks for lockers and gyms, and flexible cable-style locks for luggage zippers and backpacks.
Most models advertise simple reset mechanisms and easy-to-read dials, and reviewer summaries generally report straightforward programming. Some users note you may need to apply firm pressure during setup on certain models—check product details for 'resettable' if you need that feature.