1 x Genuine Wanhao replacement Mk9 nozzle for Duplicator 4 and 4X printers. Duplicator 4S require a slightly larger nozzle called the Mk10 (see Mk10 nozzle). These are 0.4mm direct replacements. Simply unscrew your old nozzle and replace with the new nozzle. For replacement of blocked, burnt or damaged nozzles.