Jet Black Skylight Roof Vent 420x420mm. This skylight roof vent is an ideal accessory for a motorhome, camper van or house box which requires additional ventilation. It’s also ideal for venting small spaces, the built-in 12V fan provides additional ventilation. Made from superior quality impact and UV resistant materials supplied with permanent air flow ventilation system and mosquito screen. Built in 12v Fan. Overall vent Size is 420mm x 420mm. The cut hole needs to be 355mm x 355mm. Place the internal cap (garnish) on top the roof and draw a template using a felt tip, then add another 5mm to the top and left side. Drill pilot holes in each corner and cut along the template line. Be certain to avoid ribs, braces, and electrical wiring (internally). Check that the internal cap fits through the aperture If not, cut out opening as needed and then smooth down any rough edges and primer the exposed with metal oxide paint. Make a wooden frame around the aperture to the thickness of the interned finish depth required, taking in to account the roof ply and lining. Glue the frame with Sikaflex (polyurethane) and clap in place and allow the adhesive to set. Screw the internal cap to the timber frame and seal around the lip from the top of the roof using flexible putty or Sikaflex. Place the external vent over the lip of the internal cap and mark the screw holes with a centre punch. Then remove vent from roof and drill all screw hole locations with a 1/16?? Pilot hole, and seal with primer paint. NOTE: If installing a power or lighted vent, provide power source of 12 volts DC, using 18-gauge wire. Place putty strips/ Sikaflex flex bead around the opening on roof ½?? (1.27cm) from edge of opening. Be sure putty strips cover entire area to be sealed. Use double layers of putty strip or extra Sikaflex if necessary, to seal ribbed areas. Insert vent into opening on top of putty strips. Use an screw driver or nail to locate and line up corner drilled holes with the corner screw holes in vent frame. CAUTION: Install vent with lid hinge side toward front of vehicle. Screw corner screws first to hold vent in place then screw all remaining vent mounting screws. Tighten just enough to compress putty tape. Over-tightening may cause Plastic Base Vents to crack. Using the appropriate roof coating for your roof surface, coat screw heads and vent frame edge and seal around the frame if necessary. Your installation is complete. If you are retrospectively fitting the roof vent you must take care when cutting the aperture as not to damage the existing head lining and leave enough to cover the timber frame if required. We aim to provide our customers with the highest quality of products at the best prices. We specialise in a wide range of vehicle accessories such as car cover, seat covers, camper windows, roof vents, camper lining, plywood kits and much more. Have a look through our wide range of products, we definitely have something of interest for everyone. All orders will be processed within 24 hr except on weekends and national holidays. Orders to Isle of Wight, Isle of Man, Scottish Highlands and Northern Ireland may incur an additional surcharge depending on the item. Any genuinely faulty goods will be replaced, however we must be notified of any faulty goods upon receipt of the item. Please Note: Ply lining kits are made to order and have a lead time of 7-14 days. Please note your item will not be sent out until funds have cleared and showing into our account for transfers and cheques. Send us a Message.