The Razor is a mummy version of our Fleece Cover. It can be used year round - as an accessory or as a standalone bag. It is a great "accessory", even if you already have several bags. It can help add extra warmth on those extra cold nights. As a standalone bag, it can be used in warmer temperatures when you only need a very lightweight bag. With a bag that works, whether it is warm or cold, and with mummy or rectangle bags, you can't go wrong with this choice... a value that lasts all year long!