Refurbished reasons: It comes from a return. It has signs of having been tested. The original box is not in perfect condition.Cassette sprockets for Shimano ® 12x transmissions. The structure features 10 gears made of carbon steel with matt chrome finish. The last two pinions are machined from solid and form an AL 7075 T6 aluminium alloy monoblock with Hard Treatment anodisation. Features:- Four available combinations. - The weight of the cassette in the 11/ 30 configuration is 310 g.Specifications:- Weight (g): 310 (+/-3%) (11-30T)- Middle position sprokets teeth: 16 / 17 / 18 / 19 / 20 / 21 / 22 / 23 / 24 / 25- Pole position sprockets teeth: 11+12 / 14+15 / 16+17- Middle sprokets material: Steel matt chromed-plated- Last position sprockets teeth: 27+30- Lock ring material: AL 7075 T6 / Black anodization- First position sproket material: Steel matt chromed-plated- Last position sproket material: AL 7075 T6 / HT ´´Hard Treatment´´