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 range is from 5°C to 20°C (depending on the environment and personal circumstances). Velcro Strap: The additional velcro strap helps to hold the zipper in place and prevents heat from escaping from the top of the zipper. Multifunctional Zipper: The envelope sleeping bag has a two-way zipper that runs along the entire length and width of the bag. You can either unzip for ventilation if you feel too hot, or fully unzip the sleeping bag and use it as a large blanket. Any Position: In an envelope sleeping bag, you can sleep in almost any position you want. A rectangular bag allows for 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