housing 61 is used for attaching onto the cover unit 5 the second illuminating unit 7 is detachably disposed on the plate 51 and has a second housing 71 a second ac dc converter 72 disposed on the second housing 71 and electrically connected to the main ac power a second electric capacitor 73 electrically connected to the second ac dc converter 72 a second lighting member 74 electrically connected to the second electric capacitor 73 a second lighting member 74 electrically connected to the second electric capacitor 73 a second charge indication light 75 disposed on the second housing 71 and a second magnetic member 76 disposed on the second housing 71 the second housing 71 has a second handle portion 711 and a second head portion 712 connected to the second handle portion 711 the second ac dc converter 72 and the second electric capacitor 711 are disposed on the second handle portion and the second lighting member 74 is disposed on the second head portion 712 in the preferred embodiment of the present invention two metal connecting spots 511 are respectively disposed on the plate 51 corresponding to the first and second housings 61 71 and used for allowing the first and second head portions 6 7 to be electrically connected to main ac power the second charge indication light 75 on the second housing 71 indicates the charging conditions of the second electric capacitor 73 the second magnetic member 76 on the second housing 71 is used for attaching onto the cover unit 5 furthermore the first and second housings 61 71.