An additional cover arranged to be registered with a frame cover of a cabinet , for providing the cabinet with protection from fluidic ingress, the additional cover comprising: a first portion and a second portion opposite to the first portion ; said first and second portions having first and second main sections, respectively, and first and second flanges, respectively; and a first sidewall and a second sidewall opposite to the first sidewall ; said first and second sidewalls extending between corresponding sidelong edges of at least the first and second main sections, the first and second portions and the first and second sidewalls being arranged to define a flow passage with an inlet at an upper end thereof and an outlet at a lower end thereof, the first and second flanges being provided at the inlet and outlet , respectively, to prevent fluid flow through the flow passage ; the first flange being arranged to extend from an upper edge of the first main section of the first portion and being arranged to form an acute angle (α 1 ) with the first portion at the inlet ; and a lower edge of the second main section of the second portion being arranged to terminate above a lower edge of the first main section of the first portion ; the second flange being arranged to extend from the lower edge and being arranged to form an obtuse angle (α2) with the second portion above the outlet , the respective lower edges of the first main section of the first portion , the second flange and the first and second sidewalls being arranged to form the outlet ; and characterized in that : respective upper edges of the first and second portions and the first and second sidewalls are arranged to be registered with a lower end of the frame cover defining an upper passage leading to the inlet of the flow passage . a first portion and a second portion opposite to the first portion ; said first and second portions having first and second main sections, respectively, and first and second flanges, respectively; and a first sidewall and a second sidewall opposite to the first sidewall ; said first and second sidewalls extending between corresponding sidelong edges of at least the first and second main sections, the first and second portions and the first and second sidewalls being arranged to define a flow passage with an inlet at an upper end thereof and an outlet at a lower end thereof, the first and second flanges being provided at the inlet and outlet , respectively, to prevent fluid flow through the flow passage ; the first flange being arranged to extend from an upper edge of the first main section of the first portion and being arranged to form an acute angle (α 1 ) with the first portion at the inlet ; and a lower edge of the second main section of the second portion being arranged to terminate above a lower edge of the first main section of the first portion ; the second flange being arranged to extend from the lower edge and being arranged to form an obtuse angle (α2) with the second portion above the outlet , the respective lower edges of the first main section of the first portion , the second flange and the first and second sidewalls being arranged to form the outlet ; and characterized in that : respective upper edges of the first and second portions and the first and second sidewalls are arranged to be registered with a lower end of the frame cover defining an upper passage leading to the inlet of the flow passage . <EOS>