These signs are found in various places around the country and indicate that there is a fire hydrant nearby, they are yellow with a black 'H' in the middle. The figure at the top is the size of the main that feeds that hydrant in millimetres. The lower figure is the distance from that plaque to where the hydrant is in metres. I engraved the slots into the corners where the plaque would normally be fixed and I even made some slotted screw heads from 8mm material to make it look like it is screwed down (actually in hindsight this may be wrong, stay tuned)
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