The SRAM PG-980 9-speed cassette is a kind of hybrid. The three largest steel cogs are riveted to an alloy spider for weight savings, stiffness and durability, while the remaining six steel cogs are individuals for economy. The three cogs take their spider from the ultra-high end PG-990, which has eight of the nine the cogs on a single spider and the economical PG-970 and PG-950 which have all the cogs sliding on individually. As with all SRAM cogsets, the ramps built into the cogs are the reliable PowerGlide II design. There are two different ratios, 11-34 and 11-32. Weight 280g (11-32).