Natural feather shuttlecocks from Yonex are made from Chinese goose feathers. The feathers are by-products of the food industry. The five different products vary only in quality, which is expressed by a number. The higher the number, the more stable the shuttlecock flies and the longer it lasts. AS-40 and AS-50 are recognized by Swiss Badminton as shuttlecocks for all tournaments and interclub championships in Switzerland. The AS-30 is approved for the 3rd to 5th league of the interclub championships and is known as a top-quality training shuttlecock, even among non-licensed players. The AS-30 is the best seller in the range of natural feather shuttlecocks. AS-20 and AS-10 are very good shuttlecocks that are frequently used as training shuttlecocks in clubs. Recreational players are also increasingly using shuttlecocks with real feathers, as they provide a better playing experience and a richer sound upon impact.