This ALPS Mountaineering Summer Lake Plus 55deg Rectangle Sleeping Bag, manufacturered by Alps Mountaineering, is listed with an MPN of 4902002. he Summer Lake gives you two options: you can use the top layer as a sheet by itself for warm nights when an entire sleeping bag isn't necessary, or if it gets a little bit cooler, you can simply turn the bag over and put the insulated bottom on top so you don't have to pack two separate bags if the weather is going to vary on your trip. - Rated 55-degrees F. - 1 pound TechLoft+ fill. - Poly cotton 'sheet top'. - Compression stuff sack included. - Color: Grey/blue. - Shape: Rectangle. - Material: 210T nylon ripstop. - Dimensions: 33 W x 80 L x 2 Thick. - Zipper: 8.