molly petite stuff sack stuff sack is a washable liner for your dog duvet! fits size petite round (20" x 4") molly mutt beds. stuff sack helps shape all of the old clothes, pillows, blankets to create a comfy mattress for the duvet cover when its time to wash, the stuff sack and all its contents can go right into the wash buy extra molly mutt duvets so that a clean cover is always available 100% nylon, fully zippered and gusseted