Ah, the Pharaon is too big, I think. The tank was designed to take a 35mm cartomiser, so anything else has to keep to those dimensions. Google for Katdarling's blog posts about maintenance etc of the Billet Box - really useful practical info. At the moment I believe your options are limited to a Diver v2 from Atmistique (the 35mm, Enzelis, flangeless version - can get from makers in Greece, or online from place in Canada, I read), with ceramic cup; or a Billet Bridge from same source, which takes Aspire BDC heads. There's also a co-op in USA which has made its own atty, a Sabot. Earlier modifications like the Killer and Diver v1 were not so successful. All the info is in this thread - it's a big read, but lotta lotta good stuff!!!