| 摘要 |
The invention relates to chambers which are sealed against ingress of water and are provided with an element through which air may permeate to equalise pressures of air inside and outside the chamber. The element (4) is of a foamed silicone and has a cellular fine pored layer (28) of predominantly open cells having a skin (30) to be contacted by air outside the chamber. Examples of chambers described and claimed are a vehicle horn and a vehicle headlight. |
