Shuttlecock can be natural materials, synthetic materials or use them to blend. As long as the shuttlecock's flight performance and use of natural feathers and cork ball wrapped in sheep's clothing made of care similar to the performance of the ball. 4.1 General style 4.1.1 should have 16 feathers fixed badminton ball care department. 4.1.2 feather length 64-70 mm. But a ball of feathers from each side to prop feather tip length should be consistent. 4.1.3 The feathers around the top into a round with a diameter of 58-68 mm. 4.1.4 feather line or other suitable material applied fasten. 4.1.5 ball prop diameter 25-28 mm, the bottom of the round. 4.2 Shuttlecock 4.74 to 5.50 grams. 4.3 The Shuttlecock is made of non-badminton 4.3.1 skirt-like synthetic material or feathers. 4.3.2 Shuttlecock asked if the rules described in 4.1.5. 4.3.3 Size and weight with 4.1.2,4.1.3 and 4.2; but because of feathers in synthetic materials and natural weight, performance differences can be allowed no more than 10% error. 4.4 ball test 4.4.1 test the ball, standing outside the end line, with the best low hand to move the top ball, the ball's flight direction to be parallel with the edge. 4.4.2 a normal speed of the ball should fall away from the other end line within the region between 530-990 mm. 4.5 Non-standard ball As long as the general style of ball, speed, and flight performance of the same, approved by the relevant national organizations, can be adapted for these conditions. 4.5.1 As the altitude or climate conditions, such as not using a standard ball. 4.5.2 If special circumstances, you must change only conducive to competition.