Therm-a-Rest Boost

The WarmZip™ system allows you to pull the insulation closer to your body by adjusting the center zipper. While the bag is rated for 20 degrees Fahrenheit, this feature lets you cinch the fit to trap more heat when temperatures drop, or loosen it for better airflow when the night is milder.

Yes, the arm holes are designed to provide dexterity for reading or adjusting gear while keeping your core sealed. Because they are integrated into the bag's construction, they allow for movement without requiring you to unzip the main bag and expose your entire upper body to the cold.

Absolutely. The convertible shape allows you to start with a roomier, semi-rectangular fit, which is generally more comfortable for side sleepers or those who toss and turn. If the temperature drops significantly, you can cinch it into a mummy shape to maximize thermal efficiency.

Zoned insulation means the down is strategically placed where your body needs it most, such as around your core and feet, while using less in areas where it's less critical. This design keeps the bag lightweight and packable without sacrificing the warmth you need for three-season backpacking.

Yes, the down is hydrophobic, meaning it resists moisture to maintain its loft and warmth even if it gets slightly damp. Additionally, the shell features a PFAS-free water-repellent coating to help shed condensation or light moisture.

The maximum user height for this sleeping bag is 72 inches, or exactly six feet. If you are taller than that, you may find the bag too restrictive in length, especially when cinched into the mummy configuration.