Inline Skates are designed to use on a smooth surface that is free from sand and dirt. Inline skating, like most sports, involves risk. In order to minimize that risk, you should observe the safety precautions in the manual. When making your purchase, you should choose the appropriate Inline skate for you - based on your shoe size, weight, skill level and use. EU Size 34-37 and 38-41: designed for user weight 44 – 220 lbs; Class A. EU Size 30-33: designed for user weight 44 – 132 lbs; Class B.