The 2 feet swivel out to 90 degrees. The feet are screwed or nailed from the underside into a vertical wooden dowel upstand on which the longer pvc upstand tube is screwed. The feet swing together for stacking and easier transport in a car boot. One foot is marginally shorter so that it fits within the underside of the longer foot. The longer foot has a short double thickness of wood at each end so that both feet are level when in use. The feet vary from 600mm to 900mm long - they were from scrap timber. The TVOC Emit stakes just fit inside the central upstanding pvc tube. The base of the stake rests on the internal wooden dowel which is 26mm sq x 75mm long. The pvc tubes are 175mm long x 41mm id. There are some variations as I improved the design as I went along. Ideally- if new ones are made the pvc tube should be at least 100mm longer than the wooden dowel so that the stake does not come out with rough handling.