The Mitas C-21 STONE KING front tire is designed for 50 - 100cc junior motocross and pit cross applications. This tire is designed for semi-hard and rocky terrain. The C-21 is often combined with a Mitas E-12 rear tire. Yellow stripe indicates a tire made from a softer compound for Enduro FIM and cross country competitions. Since in these races types of surfaces are alternating from soft to hard, a medium hard compound is used to deliver performance on different surfaces.