Trailhead Synthetic Sleeping Bag (-1°C & -7°C)If you are new to outdoor recreation, or you only camp occasionally, the Trailhead synthetic mummy sleeping bag is a great value option. However, that doesn't mean we've cut corners on comfort and versatility. Like all Sea to Summit synthetic mummy sleeping bags, the Trailhead utilizes WaveLoft construction to allow the insulation to expand out into air trapping curves for maximum warmth. As the temperature rises, the full length zipper (which curves