Check the listing for details. MicroSHIFT Advent MX G-Series 11-Speed Cassette with Chromoly Steel Cogs &. Color: Gray, Condition: New. Listed at 108.30 USD. The Advent MX G-Series cassette is the smoothest shifting, most durable cassette that they've ever made. That all starts with SpeedRamp, a series of discrete shifting ramps that move the chain quickly, quietly, and precisely under load. The cogs themselves have been upgraded as well: the profile has widened to 1.8mm, and the first seven cogs (11-28) have been constructed using full chromoly steel, helping to outlast even the most robust competitors.SpeedRamp technology delivers faster, quieter shifting. Thicker chromoly steel cogs from 11t to 28t provide a 500% durability increase over hi-tensile steel while the aluminum spider, 42t cog and 50t cog offer valuable weight savings. Replaceable small cogs extend service life. Nickel plated satin finish results in less visible wear. Compatible.