Airsoft is a combat sport similar to Paintball in which participants eliminate opponents by hitting each other with (6 or sometimes 8 mm) plastic ball bearings (BB's - although BB stands for 'bullet ball' in reference to Airsoft), launched from airsoft guns, that can be powered by CO2, Green Gas, spring, or electrically powered gearboxes. Participants typically use varying types of weapons designed as replicas of real firearms, tactical gear, and accessories used by military and police organizations. In North America and Europe, there is a growing interest in airsoft.