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Claim 1

AN ENCLOSURE FOR HUMIDITY SENSITIVE ARTICLES, COMPRISING: A CONTAINER ADAPTED TO RECEIVE THE ARTICLE TO BE ENCLOSED; A FILM OF THERMOPLASTIC MATERIAL LAMINATED TOA PORTION OF THE INSIDE SURFACE OF SAID CONTAINER; MEANS DEFINING AN APERTURE IN SAID PORTION OF SAID CONTAINER; A SUBSTANTIALLY TRANSPARENT WINDOW HAVING A FILM OF THEREMOPLASTIC MATERIAL ON BOTH SURFACES THEREOF OVERLYING SAID APERTURE AND FUSED ABOUT ITS PERIPHERY TO THE SURROUNDING INSIDE SURFACE OF SAID CONTAINER; AND A POROUS THERMOPLATIC BACKING MEMBER OVERLYING SAID APERTURE AND SAID WINDOW, SAID BACKING MEMBER BEING FUSED ABOUT A PORTION ONLY OF ITS PERIPHERY TO THE PERIPHERY OF SAID WINDOW WHEREBY A POCKET IS DEFINED BETWEEN SAID BACKING MEMBER AND SAID WINDOW, A PORTION OF THE PERIPEHRY OF SAID WINDOW PROJECTING FROM BENEATH THE PORTION OF THE PERIPHERY OF THE BACKING MEMBER WHICH IS NOT FUSED THERETO SO THAT SAID CONTAINER, WINDOW AND BACKING MEMBER MAY BE FUSED TOGETHER IN A SINGLE OPERATION, SAID POCKET BEING ADAPTED TO RECEIVE HUMIDITY INDICATING MATERIAL SO THAT THE LATTER IS VISIBLE FROM OUTSIDE SAID CONTAINER THROUGH SAID WINDOW.