SOL Emergency Bivvy XL with Rescue Whistle - Be prepared for the unexpected with the SOL Emergency Bivvy XL with Rescue Whistle and Tinder Cord. The extra-large bivvy design with a closed toebox helps keep warm air inside with enough space to shelter two people. The waterproof, windproof material reflects 90% of body heat while sealed seams keep out rain, wind, and snow. Start a fire with the tinder cord included on the stuff sack. The bright orange is highly visible, and the rescue whistle signals for help. Use the SOL Emergency Bivvy XL as a sleeping bag or a blanket to ensure you stay warm until help arrives.