It comprises a first member with a plate attached and substantially covering at least one portion of a second member (20), both members being rotatable relative to each other and defining a tortuous way, and it further comprises a brush sealing attached to the first member and resting on a siding plate in the second member such that an inner gap formed between said first and second members is sealed. A flexible member may be provided between the brush sealing and the first member for joining them in a flexible way.