The Dragon Puffer Airflow Indicator is only 4.75 inches High X 3.16 inches wide. The Dragon Puffer is specially designed to deliver a generous plume of non-toxic fog to test for air flow in many applications from home energy audits to testing vent hoods in labs. The small compact design is ideal for both the professional and DIY user. Simply load the Puffers Fill tank with ,the included Fog Fluid, install 6 AA batteries and the Puffer is ready to go. Included 3oz bottle of fog fluid (enough for 50 rooms).