backpack lock

Common types include keyed padlocks (mini keyed luggage locks), small keyed travel locks, 3‑digit combination padlocks, and flexible cable‑style locks designed for zipper pulls.

For locks with a reset button: 1) Align the dials to the current code. 2) Press the reset button into its groove and hold it. 3) Turn the dials to choose a new 3‑digit combination. 4) Release the reset button to save the new code. (Locks without a reset button may use a different procedure.)

Common materials include zinc alloy or aluminum bodies (often vinyl‑covered for protection), hardened steel shackles, and metal constructions for keyed mini locks. Cable‑style locks typically use braided steel cords with a vinyl coating.

Keyed locks may use pin‑tumbler cylinders or warded designs; some list 4‑pin cylinders. Keyless locks commonly use 3‑digit combination dials. Some padlocks also advertise dual/double locking levers for added pick‑ and pry‑resistance.

Typical specs reported include a shackle diameter of about 1/4 in (6 mm), shackle lengths around 0.75–0.87 in, and shackle widths about 0.5–0.8 in. Cable‑style locks list steel cords around 5.6 inches long (vinyl‑covered).

Common advertised features include hardened steel shackles, zinc‑alloy or vinyl‑covered aluminum bodies for corrosion and scratch resistance, 4‑pin cylinders, and dual/double locking levers to resist picking and prying. Some listings also note water‑ and rust‑resistant finishes.