The shimano hg40 6 8 speed chain with hyperglide ultraglide for precise shifting this chain is recommended for altus and older alivio stx drivetrains hg technology uses chamfered inner plates to optimise shifting performance on hg sprockets the mushrooming of the pins gives unsurpassed side plate retention enabling the chain to exceed the bsiso standard for breaking force and durability is assured thanks to the heat treated rollers pins and plates the chain is 73mm wide optimised fo