1.have better self-cleaning and through 2.sizes: 18.4-38,18.4-34,18.4-30,11.2-2 3.TT and TL, pattern R1.R2 F2 R1, R2, F2, RIB and LUG pattern TT and TLSIZEplyTT/TLPATTERNWeight/set(kg)18.4-3810TTR220018.4-3410TTR215518.4-3010TTR215014.9-288TTR18014.9-248TTR15614.9-248TTR15512.4-288TTR15312.4-248TTR14811.2-388TTR1 11.2-288TTR1 11.2-248TTR13611.2-248TTR1989.5-248TTR130