Dimensions and technical details Various size options: 80 - 315 mm Material: galvanised steel sheet, pressed, calibrated Double gasket: non-ageing EPDM rubber Airtightness class D according to EN 12237 Model Nominal diameter (mm) Length (mm) N 80 80 mm 8 N 100 100 mm 8 N 125 125 mm 8 N 150 150 mm 8 N 160 160 mm 8 N 200 200 mm 8 N 250 250 mm 8 N 315 315 mm 8