330-PS-3007 (USN 446565): The bulk of the Mark 4 has been greatly reduced as seen in the comparison of the old and the new. The Mark 4 is on the right. Note the better fitting pockets. Master caption: The New Mark 4 Exposure Suit. Developed by the Aeronautical Medical Equipment Laboratory, Naval Air Material Center, Philadelphia, Pennsylvania, is an improved version of the Mark 3 Exposure Suit. The new suit shows excellent floatation qualities and is equipped with quick-donning gloves, better fitting pockets, and the sleeves have been lengthened, adding thermal protection to the wrists. An insulated boot, requiring no extra heavy sock has been provided. The Mark 4 allows the pilot more mobility and the bulk has been cut down considerably. Photograph released October 13, 1952. (5/12/2015).
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