Combination locks are specifically designed for use on portable items like backpacking and camping equipment and vehicles like snowboards, bicycles and motorbikes. These locks feature a series of dials that allow you to enter the combination which will engage and disengage the locking mechanism. Once you get your lock home from the store, you will need to reset the combination from the factory standard one for a new one that you choose yourself.
Turn the numbers on the lock dials to the factory standard combination or to your current combination if you have already changed it before.
Pull the end of the lock out of the dial chamber and turn the collar at the far right end of the chamber. This collar is different than the rest of the dials and doesn't have any numbers written on it.
Keep turning the collar towards yourself until it can't turn anymore. Enter your new combination by adjusting the dials to read how you want them to.
Rotate the collar away from you until it stops and insert the end of the lock into the chamber again.
If your model of lock doesn't sound like the one described here, contact the lock's manufacturer for further assistance.
Do not use combinations that are easy to guess or common like 1-2-3-4.