The diameter of the installation bore is 25mm or 30mm,used for automation and signals in control circuits below AC 660V, DC 440V Features and specifications: 1) Basic spec code: 25mm or 30mm 2) Protection grade: IP40, IP65 3) Meets international IEC947 standards 4) The front color: red (R), green (G), yellow (Y), black (B) 5) Many types are available: pilot lamps, pushbuttons, illuminated pushbuttons and selector switches 6) Main body: made of fire resistant material 7) The structure: simple, easy to install