The test report on the Grüezi bag model 'Biopod Down Wool Subzero' was published in the 10/2019 issue of the 'Alpin' magazine. You can find out more about this in the following article for download as a .pdf file: Alpine-Issue-10-2019-Warm bed-Biopod DownWool Subzero Whether day hike, hut trek or tent tour, sleep carefree and comfortably with Grüezi bag sleeping bags!