Sea to Summit Reactor Fleece Liner

Instead of spending hundreds of dollars on a bag for shoulder season, this liner lets you take your three-season bag into winter service. The microfleece liner increases your bag’s warmth by 15 to 20 degrees or can be used on its own in more tropical climes. “I didn’t need more than the liner to stay warm in 60°F temps,” noted one tester after sleeping out under the stars on an early fall night in Kalymnos, Greece. Bonus: It has a drawcord hood and side zip. seatosummit.com