The Sea to Summit Trek Down Sleeping Bag 30 is the lightest version of the Trek Down line, tuned for the two shoulder seasons of spring and summer. EN/ISO 23537 testing gives a comfort rating of 5°C and a limit of -1°C, with the bag weighing 1,119 g.
The fill is 380 g of 650 fill power duck down with hydrophobic treatment, the tapered-rectangular cut gives room to move, and a two-way zipper allows temperature regulation as well as coupling with a second bag into a double. Both shell and liner are made from recycled 20D polyester, so the bag combines a lower manufacturing footprint with RDS-certified, hydrophobic down and PFC-free treatment.
Sized for users up to 185 cm, it packs into an included compression sack at 8.2 L; a separate storage sack is not included. Given its temperature range and use of recycled materials, it suits spring and summer trekking where the environmental profile of the gear matters, not just its weight.