SPS Offset 13 spline Front Sprocket. 10mm or 3/8th Offset from standard. Avaialble in 15,16,17,18 tooth Size. 530 Pitch Please add note to us when orderering. These make the accomodation of a wider rear wheel/Tyre Possible whist maintaining correct chain alignment. These Sprockets are made from Chrome Moly Steel Stock and heat treated. UK made. Beware of Inferior  Far East Products.