These shuttlecocks are precision designed and manufactured to provide accurate flight performance. Also, the combination of close to feather structured built up along with four to five times more durability than an ordinary nylon shuttlecock makes the Yonex Mavis series the most cost effective choice for practice sessions. The Mavis 10 shuttlecocks come with a green cap and the material combination is nylon along with smooth feathery shiny material which makes them more resistant.