650+ Loft Ultra-Dry Down
![650+ Loft Ultra-Dry Down](http://seatosummit.eu/cdn/shop/articles/Ultra-Dry_Down_650_cb03a5da-9614-4b46-a460-c3b19b3cdc72.png?v=1653006169&width=1200)
650 Loft Ultra-Dry Down is used in the Sea to Summit Trek and Journey sleeping bags. 650+ Fill Power indicates that one ounce (30g) of down will re-expand to over 650 cubic inches after compression. This down provides an ideal warmth-to-weight ratio for the traveler, recreational camper, and occasional backpacker. 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.
The down is responsibly sourced and RDS certified and treated with the environmentally-friendly water-repellant Ultra-Dry Down treatment.
All of which means you can rest easy.