Our newest accessory, the Tracer sleeping bag liner, is incredibly soft and patterned to match our Classic Spoon shape contours for extra comfort and light warmth on any overnight adventure. The physical layer helps shield your bag from oils and sweat, and Tracer is also treated with Polygiene Odor Control Technology, an antimicrobial finish that inhibits odor-causing bacteria. By allowing users to extend the time between laundering, this bluesign approved odor-free finish protects a sleeping bag's performance and longevity while also reducing micro-plastic shedding into the water stream.Tracer is made with lightweight THERMOLITE EcoMade fabric, a material woven from 100% recycled yarns with hollow core fibers. These hollow fibers efficiently trap heat to moderately extend the temperature range of your sleeping bag without adding bulk or excess weight to your pack. Though Tracer is optimized for NEMO Classic Spoon bags (Disco, Forte), it can be used as a layer inside any sleeping bag, from rectangle to mummy style.