... N550 N660,N326,N375 1.black powder granular pignent 2.usage:rubber,plastic etc Carbon black 1. Type: n220,n330,n550.n660,n326 ... ,n3752. Place of origin: china3. Standard: GB 3778-20034. Form: black granule ... +/-1.3-1.7 +/-1.3-3.5 +/-1.3 Carbon black N330