購物知識：羽毛球

發現羽毛球包裝面是有重量編號的，通常為 76, 77... etc
再留心看，「飛機牌」又用49, 50...etc.

原來羽毛球編制有兩種：
格林制76,77(較少78) (mainly Europe)
(或重量制49,50,51)

Also, the choice may be affected by temperature...


"The speed 49,50 or 51 is the weight in Grams, 4.9g, 5.0g or 5.1g, and 76, 77 or 78 is in Grains, the conversion between these two unit is 1g = 15.43 Grains, so

4.9g = 75.6 grains
5.0g = 77.2 grains
5.1g = 78.7 grains"

夏季一般用76的，冬季用77或者78的

http://www.badmintoncentral.com/forums/showthread.php?p=1395358

interestingly, This information is not found in wikipedia
http://en.wikipedia.org/wiki/Shuttlecock

P.S. Thanks Mr. Lai for the initial introduction to numbering...