An assembly for sealingly enclosing a space into which one or more optical fibres and/or optical cables is or are fed includes a container defining the space and a sealing member. The container has an opening therein. The sealing member sealingly encloses the one or more optical fibres and/or optical cables positionable distinctly and separately from the container. The sealing member: (a) can be placed in the opening so that the one or more optical fibres and/or optical cables extend through the opening into the container, and (b) can be heat and/or pressure sealed to the container to seal the opening around the one or more optical fibres and/or optical cables.