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This cabinet wrench is a three or square, narrowing Exagonal key, sometimes combined with one or more socket wrench(es), also with a screwdriver, with which doors and locks of cabinets etc. in carriages or ships can be opened or tightened. Construction workers such as the locksmith, carpenter and painter sometimes use a this wrench when there is no door handle in the lock, eg on a construction site.

There are foldable models. The wrench also comes as part of a folding knife for construction workers. [MOT]