Size and Suitable Temperature: The overall size of this sleeping bag is 180cm long and 75cm wide, the hood is 30cm long. The recommended temperature limit is from 5°C to 20°C (depending on the environment and personal circumstances). Velcro Strap: The extra Velcro strap helps to keep the zipper in place and prevents heat from escaping from the top of the zipper. Multifunctional Zipper: The envelope sleeping bag has a two-sided zipper, which runs along the length and width of the bag. You can either open the zipper for ventilation if you feel too hot or fully open the sleeping bag and use it as a large blanket. All Positions: In an envelope sleeping bag, you can sleep in almost any position you want. A rectangular bag allows more freedom of movement and a variety of sleeping positions. Popular Choice: Rectangular sleeping bags are a popular choice for car campers. You can bring a rectangular sleeping bag to the campsite, and this one is a warm and spacious option for families and car campers._NANA