... after-sales serviceFactory Direct,OEM.earphones used for MP3,MP4,CD,Iphone,computerProduct sepecifications:1. ... material of your skull earphone ,the plastic or metal ?For this earphone ,it is plastic . 2:What ... size ,large size ,Middl size and small size .For the color ,black ,white,transparent white ,grey ... 3:How is your earphone sound quality ?For our metal earphone ,the most character is that bass ...