Wikipedia
In German-speaking countries, the miner's toolset is known as a Gezähe (derived from gizouuun, zu zawen, gezawen – to be usable, advantageous) formerly also abbreviated to Gezäh. It is a set of personally-owned mining tools and equipment needed by the miner in his daily work.
In coal mining in central Europe during the 19th and 20th centuries, every miner had his own set of tools. So that they could not be stolen, before the end of his shift they were either locked in a tool chest (Gezähekiste) or threaded onto a tool ring (Gezähering) which was then locked. To that end, all tools had a hole or eyelet. Tools that were not part of a miner's personal equipment and were only needed now and then, could be issued to the miner in the tool store (Gezähekammer or Magazin) in return for a token (Gezähemarke). Most tools were either marked with a number, which was either tapped or welded to tool.