What is "stackhat"

The Stackhat, originally designed as a generic sport safety helmet by CIG (Commonwealth Industrial Gases, now BOC) and then developed by Rosebank, was a bicycle helmet widely available in Australia in the 1980s. Due to government regulations and promotion by various State governments, the sturdy bright orange Stackhat had a near monopoly on bicycle helmets in the country for teenagers and children. Its distinctive design, initial release in a bright orange colour, ubiquitous ownership in the 1980s, and fast disappearance in the 1990s, have combined to make "The Stackhat" a defining symbol of the 1980s for Australians. While the variety of helmet colours expanded throughout the years, the design did not.