A hoop is an apparatus in rhythmic gymnastics and may be made of plastic or wood, provided that it retains its shape during the routine. The interior diameter is from 51 to 90 cm, and the hoop must weigh a minimum of 300g. The hoop may be of a natural colour or be partially of fully covered by one or several colours, and it may be covered with adhesive tape either of the same or different colour as the hoop.