you remove from your SunRace CSMX3 10speed 11/42 cassette the cogs 15T or 18T (depending on your needs) and you replace it with ARI 44T, 45T, 46T or 48T upgrade cogthe spacer given with the cog has to be inserted between ARI and the original 42T cog, without any additional modification on your bikereplacement is easy and fastin the mounting section you can find some helpful suggestions for the mounting and correct regulationsmaterial used is hard anodized ERGAL 7075T6all range of colors is available in the colors chart at this linkweight of 44 teeth cog is 86 gramsweight of 45 teeth cog is 92 gramsweight of 46 teeth cog is 99 gramsweight of 48 teeth cog is 110 grams
ARI spare/upgrade cog for SunRace CSMX3 11/42 10speed cassette