The fan I used was an unused fan from a BitFenix Shinobi XL Tower computer case:-

BitFenix Spectre™ fans. 230mm diameter

The Boost convert:-

Boost Buck Voltage Module Step Up/Down Converter Regulator 3-35V or 2.2-30V eBay Seller Seller :accecity-ca

The carbon filters Carbon Fibre Oven hood filters, these come in a sheet that may be cut to size, with care you will most likely get two. ( I use a bigger and a smaller filter as a double filter), lots of filters to use:-

Carbon Universal Cooker Hood Filter 47cm x 57cm eBay Seller reliant-cleaning-services

Cardboard Box to fit it all in

Rocker Switch, before the Boost Converter so when turned off no power is used by the Boost Converter

USB Cable and other cables, etc..

Hot Glue

Solder and soldering iron

Heat shrink tube where required