When extra thermal protection is more important than shaving off the grams, the Thermic Expedition Sleeping Bag Liner is the go-to sleep system upgrade.Conceived as an accessory for the uncompromising Rab Expedition collection, the Thermic Expedition Sleeping Bag Liner adds some useful extra insulation courtesy of its Thermic microfleece construction. Built with a traditional mummy cut, it weighs 500g and provides exactly the protection your Expedition Sleeping Bag deserves. Thermic Expedition Sleeping Bag Liner