SKU: SS22863 Weighs: 501g R-Value: 7.1 Season Rating: Winter Mat Size: Regular Mat Type: Airbeds If you are looking for an 'extreme cold' mat and can sleep well on a standard sized Mummy shaped mattress then at just 501grams this mat delivers superb performance for its weight. Exped says: The Exped Ultra 7R M M… Ultra 7R M Mummy Sleeping Mat