| 摘要 |
A retro-reflective device comprises a white retro-reflective portion and at least one further retro-reflective portion displaying a blue or red colour. The white retro-reflective portion has a performance of less than 180 cd/lux/m<2> and the coloured portion has a performance of at least 10 cd/lux/m<2> when blue and of at least 15 cd/lux/m<2> when red. Such performance is measured in accordance with the requirements of British Standard 873 parts 6 and/or 8 (1983) at an entrance angle of -5<o> and an observation angle of 20'. <IMAGE> |
