Nylon Material: [shell] 15D nylon ripstop, [lining] 15D nylon ripstop Insulation: 800-fill DriDown Waterproofing: hydrophobic down treatment (PFC-free) Shape: mummy Zipper: zipperless design with integrated comforter SO LIGHT AND SO COMFORTABLE….IT'S LIKE SLEEPING ON A CLOUD. "The Best Sleeping Bags and Pads of 2018: Best For Backpacking" - Outside Online “One of the best sleeping experiences of any bag we tested” – Backpacker Magazine