The days are getting shorter, but you're not ready to pack up the camping gear and start praying for snow just yet. Whether winter is just around the corner or has just said its farewells, chilly shoulder-season backpacking trips won't be so chilly in the Sea To Summit Trek TkII Sleeping Bag. The 650-fill down insulation will keep you warm on cold nights, whether they find you in the desert or the mountains. And thanks to Sea To Summit's Ultra-Dry Down technology, your down insulation won't lose its loft if you find yourself in wet and cold conditions, or if your bag happens to get wet throughout your travels. Verrtical baffeling in the chest prevents the down from shifting sideways as you sleep, keeping the warmth where it's most effective and not anywhere else, while a 3D sidewall baffle lets the down loft all the way to the very edge of the bag, ensuring total warmth. A draft collar around the neck and a full length draft tube along the zipper prevent cold temperatures from creeping in, and if you end up wanting some ventilation in the night you've got two-way functionality on the main and footbox zippers. To keep a phone or headlamp close by you've got an internal stash pocket, and to guarantee that your whole body is warm there's an adjustable mummy hood.