Mountainsmith Boreas 40 Degree Synthetic 

"the sleeping bag is great for summer camping! the semi rectangular design is great,if like me,most mummy bags constrict your movement making you feel you're sleeping in a straight jacket. while at the same time eliminating unwanted weight and size of a traditional rectangular bag. the sleeping pad loops are a great addition as well. the only cons that I found is that the hood does not cinch down with a draw cord, and that it does not have a draft tube of any kind running the length of the zipper. overall I feel the bag is a GREAT product even without these additional features if used as a summer sleeping bag."