Vango ultralite pro 300 sleeping bag the vango ultralite pro sleeping bag is designed for year round explorers who demand low weight and small pack size the wicking 4t synthetic insulation structured in a trilateral construction improves warmth reduces cold spots and conforms closer to the body thermal reverb redirects heat radiated from the body back to the user making the bag warmer this compact lightweight omega shaped sleeping bag is ideal for trekking guaranteeing a comfortable war