--  Integral stamping spherical shell, beautiful shape, compact structure.
      --  Special seal design, can effectively prevent material channeling, leakage phenomenon.
      --  The movable flap adopts the rotary form and adopts the thick wear-resisting material, which has a long service life.
      --  The Shell is of assembled structure, which is convenient to replace the movable flap plate and saves the use cost.
      --  Optional pneumatic control, electric control or manual control.