They have a conical shape and are made of 16 bird feathers, which overlap and are connected by thin threads. One end of each pen is firmly fixed in a round plug (the head of the shuttlecock), thus obtaining a shape like a flower and the shuttlecock acquires certain aerodynamic properties. The cork is covered with thin leather or synthetic material.
Feather flounces for badminton are made only from the left wing of a goose or duck.
Special aerodynamic property of the pen shell is the ability of the ball to always fall so that the head was found. This quality allows players to "lift" the shuttlecock from a variety of difficult situations and better control the ego.