2-Set Waterproof Windproof Bag with 1 Whistle Lightweight Pouch Bag for Travel and Hiking

On Rakuten, one unit costs 2,380 yen.

[EMERGENCY WARMTH] Made from Mylar, it is windproof and waterproof. When used correctly, it can retain up to 90% of your body heat. Taped seams for added strength and durability.
[HIGH VISIBILITY] The bright orange exterior is easy to spot even in bad weather, helping rescuers find you.
[FOR OUTDOOR EMERGENCIES] This lightweight and compact thermal sleeping bag is perfect for backpacking, hunting, camping, and other wilderness adventures. Keep it in your home emergency preparedness kit or in your car for winter travel.
[PACK & SIZE] Comes in a 2-pack of emergency sleeping bags with whistles. It can be compactly stored in the included stuff sack. This bag is large enough to cover you from head to toe and small enough to fit in your pocket.
[REUSABLE] This is not a single-use bag. Please fold it carefully after each use. In an emergency, it can be used on its own or as a liner for a regular sleeping bag.