SLX is the new groupset from Shimano with options designed to cater for the differing needs of the modern day trail rider. SLX borrows elements from both the new XT group (Shadow rear derailleur, composite middle ring & Servo Wave brake levers) & the best bits of the LX & Hone ranges it replaces to offer durability & high performance at a sensible price. The Shimano HG80 SLX 9 Speed Cassette is available in multiple tooth configuration options.