With integrated distance markings (box distance scale) for up to 3 flush-mounted boxes and an edge distance marking at 150 mm. All Wiha folding rules comply with accuracy class III (tolerance of ±1.4 mm). Large folding rule with integrated cable pulling aid (integrated holding function) for cables in the range of 3-7 mm, which facilitates cable routing in hard-to-reach installation environments. Sectional ruler for electricians, tested at 10,000 V AC and suitable for 1,000 V AC (insulated up to 1,000 V) + angle function = locking at 90 degrees and 180 degrees. Material: The folding rule is made of glass-fiber reinforced polyamide. This plastic is scratch and abrasion resistant, particularly bend-resistant and stable, chemical-resistant, and does not swell upon contact with water. Electrician's tool: The black markers indicate the distance between two crossbars. The distance between the crossbars is standardized, so you know where you can drill in the wall and where you cannot.