SPS Offset Front Sprocket. 16mm or 5/8th Offset from standard. Available in 17,18 tooth Size. Please add note to us when ordering. These make the accomodation of a wider rear wheel/Tyre Possible whist maintaining correct chain alignment. These Sprockets are made from Chro Moly Steel Stock and heat treated. UK made. Beware of Inferior  Far East Products.