coupling size:3"-12" with iso9001, CE and WRAS certificate ... Hydrostatic testing conform to standard of AWWA/ANSI C219Center SleeveRolled Steel to BS EN 10025-1993 Grade S275End RingsDuctile iron ... (mm)Bolt Length (mm)80Ductile Iron,PVCu,Cast Iron,Steel,Cast Iron Met&Imp AC88.1-102.4M12*1753"100Ductile ... .1-235.0M12*2008"250Ductile Iron,PVCu,Cast Iron,Steel,Cast Iron Met&Imp AC272.0-289.0M12*21510" ...