| 摘要 |
A face mask comprises a sealing collar ( 1 ) extending around the mouth with a shelf ( 4 ) extending under the nose supporting a gel insert ( 7 ) that makes sealing contact between the nostrils and a passage ( 6 ) through the shelf. A curved, rigid window ( 30 ) is a push fit in a central opening ( 2 ) of the collar ( 1 ) and has a gas inlet ( 33 ) attached with it so that the window can be removed or connected with the sealing collar as necessary. The collar ( 1 ) supported on the head by a harness ( 20 ) having two triangular portions ( 21 ) on opposite sides encircling respective ears. |
