Sea to Summit Spark SpIV Sleeping Bag, Grey/yellow

Our Spark™ Series bags are what you reach for when you need a high-performance sleeping bag but don’t want to be weighed down by one.The Spark™ Series spans everything from an ultralight liner to an expedition weight mid-winter bag. While the end-user is very different, they reflect a design ethos of matching weather conditions to the lightest bag possible.50+ Fill Power indicates that 1 oz of down will re-expand to over 850 cubic inches after compression. Higher loft means that less down can be used to achieve the same temperature rating – important for performance sleeping bags. The loft and down quality/composition are independently tested by the International Down and Feather Laboratory (IDFL) – a copy of the certification is supplied with every Sea to Summit sleeping bag.ULTRA-DRY Down™ is a permanent nano-level water repellent polymer treatment applied to our down which protects it from external moisture and condensation from inside the bag virtually eliminating the negative effects moisture has on down.FeaturesUltra-light and technical, our Spark™ Series bags are designed to keep you as warm as possible while minimizing packed weight and size.Contoured mummy shape for efficient insulationExpedition mummy bag sizing provides extra space for layered clothing or extra wriggle roomUpdated sizing provides extra room for both shoulders and hips while still maintaining insulation efficiencyIncludes lightweight Ultra-Sil™ Nano compression bag for compact storage