Material polyamide reinforced with fibre glass is scratch score and bend proof resistant to chemicals and doesnt swell with water contact joints play free wear free and dirt resistant joint with spring pin for constant tension handy 90 latching for all joints scale deep embossed black scale in 1 mm increments every 10 cm is marked in red accuracy ce conformity eu standard accuracy class iii extra readable from both sides through a second backwards running scale recto verso