A standard padlock limits the size and number of items you can lock together. A cable locks gives you more flexibility in what you lock together and how you lock it. You can weave the cable into more difficult to reach places
TSA locks allow US customs access to your lock. Customs are entitled to look in any luggage being transported and may cut off locks to access bags. A TSA lock means they have the master key to access the lock, so that they can unlock and relock your bag without damage to the lock.
The keyhole is only for TSA (US customs). You need the combination to open the lock.
The instructions for setting the combination lock are as follows. The original number is 0-0-0. To set your personal combination, follow these steps: Put the dials at its correct combination of numbers (0-0-0 to begin with); Press down on on the open button to release the cable. Push in the reset button with a pen or tool while you turn the numbers to set your own combination. Release the reset button, lock the cable back into place, and scramble the numbers. Now you have finished setting your personal combination. Please remember your personal combination or write it down in a safe place. Please repeat the above steps to reset the numbers. You need the current combination to change it to a new combination.