on the housing 31 of the steam brush set 30 for the assembly of the external knob 10 the front portion of the housing 31 of the steam brush set 30 is extended down with an insert head 36 the two sides of the central portion of the housing 31 of the steam brush set 30 are extended down with an insert head 37 each a catch groove is disposed at the rear of the housing 31 of the steam brush set 30 for holding the overturn catch head 491 of the base set 40 the rear portion on the lower surface of the housing 31 of the steam brush set 30 is disposed with an electrical outlet for energizing the base set 40 please refer to the fig7 and fig8 with combination with the fig1 the housing 41 of the base set 40 is disposed without a handle the central of the housing 41 of the base set 40 is disposed with a concave accommodation room 48 to accommodate and catch the lower portion of the steam brush set 30 the central of the accommodation room 48 is disposed with a circular pipe shaped boss 42 extending upward the upper surface of the boss 42 is disposed with an upward cog 43 the heating pan 44 is disposed on the bottom of the housing 41 of the base.