The Sub-Zero strap is specifically designed for those who want to secure multiple quilts to their pad as part of a layering system, so you can stay warm no matter the temperature. This is most commonly done using a shoulder season Revelation or Enigma down quilt with a summer-weight synthetic Prodigy for use in below-zero temperatures, though it will work with any pair of Enlightened Equipment single-person quilts. Sold individually. 0.4oz / 11g each.