Basically, it is a copper tube through the top of the vodka container with a couple of ½” holes towards the rear of the pipe. A champagne cork was drilled/gouged out to fit the main pipe into. Then the whole cork was drilled to fit a much smaller tube (I used a crochet knitting needle which has a hole about the size of a matchstick) This tube mouth was about ½” ahead of the holes in the main tube to create a vortex with a vacuum behind which sucks the smoke out of the burning chamber. An air bubbler (the kind you use to keep live baits alive in a bucket or an aquarium bubbler) is attached to the outside end of the smaller tube as it protrudes from the cork. A 1” diameter air hole is made in the side of the can at the bottom to be able to ignite the saw dust..

Half fill with saw dust and ignite with the air pump turned on and away she goes. I ran for 2 hours last night on a couple of handfuls of saw dust.