| 摘要 |
<p>A cassette (1) comprises a housing (3) with two parallel main walls (5, 7), of which one wall has a recessed portion (25). The recessed portion (25) accommodates an element (22) whose picture side (23) is visible. The element (22) can be fitted in the recessed portion (25) in only one position owing to the provision of off-centred projections (33,35). <IMAGE></p> |
