We are talking here about small kites , from 1.3m2 to 4m2. Simple to use , you don't have to have had a course  to pratice with it but it s strongly recommand to at least read the Manuel insde of the bag or watch some youtube videos. THey will help you to understand and feel the principe and power of the wind window .More hours you spend on your trainer, faster you ll learn with the big one in the water. A bigger size will give you more traction sensations but can be more dangerous to.