For top ranked professional rikishi, it is made of silk and comes in a variety of colours. It is approximately 30 feet (9.1 m) in length when unwrapped, about two feet wide and weighs about 8 to 11 lb (3.6 to 5.0 kg). It is wrapped several times around the rikishi and fastened in the back by a large knot. A series of matching colour, stiffened silk fronds, called sagari are inserted into the front of the mawashi. Their number varies from 13 to 25, and is always an odd number. They mark out the only part of the mawashi that it is illegal to grab on to: the vertical part covering the sumotori’s privates, and if they fall out during competition the gyōji (referee) will throw them from the ring at the first opportunity.