The lightweight, highly visible Survive Outdoors Longer (SOL) extra large Emergency Bivvy with Rescue Whistle is large enough to shelter two people in an emergency. It is designed with a closed toe box that helps keep warm air inside. The waterproof, windproof material reflects 90% of body heat while sealed seams keep out rain, wind, and snow. The attached tinder cord drawstring can be used to start a fire and the bright orange rescue whistle can signal for help.