Therm-a-Rest Boost 650 20F/-6C Regular Wide Morning Blue

Comfort doesn't come in a one-size-fits-all, which is why the shape of the Boost 650 can be individually adjusted to find the perfect balance between freedom of movement and warmth. As a spacious, semi-rectangular sleeping bag, the Boost offers the necessary space for side sleeping, turning, spreading out, and relaxing. The semi-rectangular shape provides significantly more room inside than a mummy sleeping bag – you feel free and can sleep in any desired position all night long. However, more space requires more body heat to keep warm. This is where the WarmZip comes in. With the high-cut zipper, the shape of the Boost 650 transforms from a semi-rectangular sleeping bag into a heat-efficient mummy sleeping bag. This redistributes the down around the body and reduces the space needed for warmth. With the WarmZip, the thermal performance of the Boost can be increased by up to 6 °C. Standard features from Therm-a-Rest include a loft.