Many people buy suitcases to carry their luggage when they go abroad on holiday and never take the trouble to find out whether they will be strong enough to survive the journey. Whatever case you buy - and obviously the more you pay for it, the better it is likely to be - you should be careful not to pack too much into it. A lot of passengers do so and then the locks break. Some people think manufacturers should say how much the case can carry. But the manufacturers say it depends on the quality of the case. A cheap case, which has been badly made, will obviously not last as long as an expensive one.