We ordered the 2.5m x 1.5m Korniche 4 pane lantern from Express Skylights in July 17. I had great help from Anne-Céline who supplied the details for the size of the upstand. There was a lead time of four weeks due to Covid. The item arrived on 18th August in very well wrapped packaging. It was the easiest roof lantern to assemble (even the builders commented on this). All the frame pieces snap together easily and then screwed tight. Only the base required minimal sealant. It raid heavily just 2 hours after it was installed. Needless to say it was clear of any leaks. The self-cleaning works quite well. The rain will wash most settled dirt off the glass. Nothing has stuck to it permanently yet. It has let in a tremendous amount of light into an otherwise dark extension. We are very pleased with then lantern. At the price of £1340.40 delivered for a full aluminium framed roof lantern, grey outside and white inside and takes less than an hour to assemble it's a steal! We would recommend this excellent product from Express Skylights to anyone looking a roof lantern to brighten their house.