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 around through the foot box) allows you to sequentially increase ventilation to the point where the mummy sleeping bag can be opened flat and used as a quilt.The tapered-rectangular mummy cut of the Trailhead gives you plenty of room to move, regardless of your sleeping position.