MATERIAL: Cr-Mo steel (ASM 4140) heat treated
SPEC: TRSK-BSH-NW = 0 offset
          TRSK-BSH-NWOF3 = offset 3mm for OLD 142mm
          TRSK-BSH-NWOF6 = offset 6mm for OLD 148mm
TEETH: 14T, 16T, 18T, 20T
OPTION: N.E.N finish or ED, BK