Western Mountaineering Sonora Sleeping Bag Liner

I've had this for almost a year now, and I finally got the chance to use it and boy, it sure does the job it claims it will. I have the Alder 25 degree bag and the forecast was for temps down to 12 degrees, so I busted this liner out and put it to use. First off, its very soft and felt more like a nice bed sheet than anything else. But the more impressive part was how comfortable I felt through the whole night while it got down to about 10 degrees outside the tent while I was nice and toasty inside this liner and my 25 degree bag. I thought for sure it hadn't gotten as cold as forecasted, but my frozen water bottle next to me and the thermometer on my watch I hung on the outside of my tent confirmed that it had indeed!