The Yonex AS-50 Shuttles are top of the line and used in all major badminton tournaments. This Yonex Shuttlecock is the best, top of the line playing piece available. This shuttlecock is used in all major badminton tournaments including the prestigious Grand Prix International. The goose feathers are of a special high grade to help stabilize the shuttlecock while it soars over the net. The durable materials ensure prolonged use over long periods of play.