Even if you use these cable locks, I can still break into your luggage. Google OPEN LUGGAGE PEN and watch the shocking video. You would be better off buying Lewis N. Clark Tsa Lockdown Triple Security Cable Lock also sold here at Amazon.com. The principle is by securing your zipper handles to the top suitcase handle the thief cannot close the zipper once he opens your bag with a pen. Always carry your valuables with you in your carry-on. Leave your jewelry at home and take cheap immitations. You can take aboard a backpack and a carry-on luggage. I once took carried an additional 50 pounds this way. BE prepared. There are lots of crooked baggage handlers, opportunistic passengers, and sticky-fingered TSA agents.

Addenum: I have invented a way to deter thieves with pens. Take an awl and make two holes through your luggage fabric right next to where your two zippers rest after you zipper your bag closed. From the inside insert the cable's end through the hole and back in through the second hole. Now lock it from the inside. Use the second lock to lock the two zippers and the first cable together. If they open your luggage with a pen they cannot close it and you will discover the crime. The thief will know he can't close it so will not try. Now need to brainstorm how to keep the dirty TSA agent out. They worse than Al Queda! Maybe make a 2-3 foot long cable with loops at both ends at Home Depot. String your shirts, pants, shorts, sandals, etc. and lock them to the cable lock inside the luggage. They can open it but can't steal your clothes. Just carry the rest of your valuables in your carry-on. Try buying a Samsonite Cruisair luggage. It has NO zippers and a built in 3-number dial a combo. Hope all this helps. I hate thieves who ruin my vacations.