Solo 365 ES3 Smoke Detector Tester Cartridge for the Solo 365 smoke detector testing system is a non-pressurized and non-flammable cartridge that can easily be stored and transported without any specific safety measures, unlike the aerosols used by standard testing equipment. With a comparable test capacity to the Solo A3 and A10s aerosols when used as per manufacturer recommendations but at a greatly reduced size and weight, spare cartridges can be carried without worry or burden meaning there will be no need to return to the van when they run out.