Are you travelling to or by way of the Unites States and intend to lock your luggage? Then use a lock that the American government (Transport Security Administration, TSA) can easily recognise and unlock, as locks that are not recognised during a TSA control in the United States may be forced open.
These ‘TSA Luggage Locks’ can be bought at Schiphol Plaza from Paolo Salotto Luxury Leather Goods and other participating stores.