Teeth made of high-strength steel, for an extra long service life Aluminum center section, reduces unsprung masses Permanently joined together with high-strength rivets At least three times longer service life than other aluminum rear sprockets 50% lighter than steel rear sprockets Longer service life of the entire drivetrain kit 5841005105004 ONLY ONE 50-TOOTH SPROCKET SHIPS. Please ensure fitment prior to purchase. If you have questions, please contact the seller. Not responsible for improper or ill fitment due to incorrect year, make & model given by buyer upon purchase.