| 摘要 |
<p>The invention relates to a device for power and telephone ducts which is used to plug or seal said ducts in order to protect networks against sludge, odours, rodents, water, etc. The inventive device is made from a mixture of synthetic and natural rubbers and comprises a body in the shape of a slightly truncated cone consisting of two peripheral rings. The upper face of said device comprises numerous openings of different diameters which are closed on the opposite side or base but which can be opened when necessary.</p> |
