I read all of the reviews prior to ordering two bags for our European trip.  I noticed that the keys were interchangable.  What would that mean:  buy a bag and now you can open anyone bag.  The top could have had interwoven metal mesh in it, but since it doesn't, it can be easily cut open.

I will still use it because it will deter the small time thief.  Also the dimension are small, it's large enough for a 10" tablet.  Other review indicated it was very large, it's not.

Buy your own combination lock.