Convenient, comfortable, lightweight and packs away into its own 3in x 5in sil nylon stuff sack that takes less room than a fleece and will be easy to locate due to the bright yellow case in your camping gear. The mummy shape that has a box foot is roomy and comfortable for a day nap and for night sleeping. The 8.7oz weight along with the added warmth of 15 degrees Fahrenheit or 8 degrees Celcius will be added to your sleeping bag warmth. This Sea to Summit Reactor Thermolite Sleeping Bag Liner is made from a hollow core fiber that provides extraordinary warmth for its weight and remains extremely breathable. The dimensions of this convenient liner is 36in x 84in in length and can be used alone, or in your sleeping bag to help to keep your bag cleaner and warmer all week long, or while you are on those three day weekend trips. Features: Adds up to 15 degrees Farenheit, 8 degrees Celsius of warmth to sleeping bag, Lighter in weight, packs better than fleece, 36in x 84in (90cm x 210cm), Made from Thermolite, a hollow core fiber that is breathable, Used to protect inside of sleeping bag, or by itself. Model Year: 2014, Product ID: 282866, Model Number: 119-REAC, GTIN: 9327868000197