1. External switch mounting box 2. OEM service provided 3. Easy install, easy wiring External Mounting Boxes For Wall SwitchesModel No.: 0020907Unit size:85mm x 85mm x 32mm Used for Wall Switch.Internal Mounting Boxes For Wall SwitchesModel No.: 0020906 Unit size:78mm x 78mm x 38mm Used for Wall Switch.Internal Mounting Box For Wall Switch US Style Model No.: 0031158Unit size:101mm x 67.5mm x ...