N-220 : (ISAF) Intermediate Super Abrasion Surface
N-330 : (HAF) High Abrasion Surface
N-326 : (SRF) Semi Reinforcing Surface
N-375 : (HAF-HS-Imp) High Abrasion Surface-High Structure-Improved
N-339 : (HAF-HS-Imp) High Abrasion Surface-High Structure-Improved
N-550 : (FEF) Fast Extrusion Furnace
N-660 : (GPF) General Purpose Furnace