The only other assembly required for the Flowtron was inserting the octanol cartridge, which slides conveniently to the cartridge holder on The underside on the device. The cartridge lasts about 30 days and costs about $15 for your replacement 3-pack. For the duration of my screening, I checked out https://outdoor-bug-zapper20730.blogunteer.com/28133044/the-flowtron-mosquito-attractant-diaries