to certify: That the Pipe Coupling With O-Ring Seal with type designation(s) VOSS 24° DKO taper couplings made of carbon steel and stainless steel Issued to VOSS Fluid GmbH Wipperfürth, Nordrhein-Westfalen [...] standard Fittings Carbon steel with VOSS coat corrosion protection ISO 8434-1 1.4571 Tubes,2,3 Carbon steel DIN EN 10305-4 Stainless steel DIN EN 10305-1 O-ring (standard) FKM VOSS Fluid Notes 1 For detailed material [...] Series VOSS, 1K 16S O-Ring (FKM) Color Green Nut Size, suppliers mark M24, 86 Periodical assessment To maintain the validity of the type approval certificate, periodical assessments at manufacturing place