Chase Skidmorewrote a review of Kelty Sine Sleeping Bag: 35 Degree Down on June 14, 2017
I needed a summer bag, that was lightweight and packable, and that wouldn't be too hot. The Sine 35 checks all of the boxes. I've found I like leaving my feet in the bag, but unzipping the lower zipper and that will get me just enough venting. It's very light and packs nicely. The Arc zipper took a couple nights to get used to over a traditional mummy but I really like how it works now. I've only used this bag for summer nights, but it wasn't too warm for some 55 and 60 degree nights with the venting open and no rainfly on the tent.