The Spark Pro has been optimized for comfort, versatility and light weight. Our highest-lofting down - 950+ fillpower RDS-certified goose down with a non-PFC Ultra-Dry Down treatment - is wrapped in extremely breathable 10D fabrics. The Free-Flow Zip system ensures maximum ventilation and the flexibility to open the bag flat as a quilt. Zip a Spark Pro to a Women's Spark and share the comfort with your companion. DESIGN & DETAILS: RDS-certified, 950+ fillpower goose down with a non-PFC Ultra-Dry Down treatment for maximum thermal performance Featherweight 10D nylon shell with non-PFC DWR, and a highly breathable 10D nylon liner for enhanced comfort Free-flow zip system, YKK #5 side zipper with zipper plow for reliable, snag-free operation. YKK #3 footbox and shoulder zipper for minimal additional weight Technical hood, anatomical footbox and an ergonomic mummy shape-ultralight doesn't have to mean ultratight Front draft collar is fitted around the neck and oversized at the shoulders to retain warmth Hybrid box baffles in torso/sewn through in leg area (-1degC|30degF) or full box baffles for maximum warmth (-9degC|15degF) TECHNOLOGY: Ultra-Dry Down(TM) uses a non-PFC hydrophobic treatment to ensure it absorbs less moisture and dries more quickly