The Mountain Equipment Ion Bivi is super lightweight, it is designed as a sleeping bag cover or very occasional bivi. Ideal for protecting down bags in damp conditions such as snowholes or for giving an extra protection layer when sleeping out under the stars.The DRILITE Loft outer shell is highly water resistant and breathable. The Ion Bivi features a large cowl over-hood with drawcord adjuster and an offset sharks toe foot piece for greater protection.    Ion Bivi Bag