Ok, a combination lock, and I shot it in the Amazon offer. The reduced price is ok, because it is only for my 1 day trolley and not the weekly trip. But the regular price is too expensive, so the stars in the devaluation, since price is low power. For the same price, there are also in the Amazon Identical TSA combination lock. This can be opened by security personnel at the airport with a special key. The sold here can be opened only with bolt cutters.
Otherwise, it is a good and sufficient lock that prevents fast times just makes someone tampering with the suitcase.