Shimano Deore XT 10s Double Chainset. Originally marketed as DYNA-SYS (Dynamic System) C-rings I.d'd by a '10S'. 170mm crank arms. FC-M785 SG-X 10s 40-28 (AJ Group). & a few newer XTR/XT bits too. Manufactured in 2011 (MY2011).
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