The bus - Kowloon Motor Bus introduced a total of 370 eleven metre non air conditioned Dennis Dragons between 1986 and 1994. A batch of 50 vehicles S3N271-320, delivered during February and March 1994, were installed with the necessary ducting for air conditioning, but it did not carry the plant itself, giving the option for fitting at a later date. As a result, there is no lower deck rear window. No air-conditioning was in fact ever fitted. S3N290 was first registered on 25th February 1994 and withdrawn on 25th February 2011.