Each group consists of 2-6 cover hairs, the cover hairs have follicles of their own and each of the cover hairs has sebaceous gland and sweat gland.
毛囊群由2—6根粗毛组成，粗毛有独自的毛囊，每一毛囊有皮脂腺和汗腺。
2
A valve body is connected with a tower cover through soft seal, and pressed by a bracket through a bolt. The valve rod, the tower cover and a gland are pressed and sealed by filler.