While our ULTRA-DRY Down is a tremendous insulator that can shrug off condensation within your tent, you may well find yourself in a situation where it might not actually be appropriate for the situation. In relentlessly wet environments synthetic sleeping bags are king and the better more sensible option. The synthetic insulation will still perform and trap warmth if damp or wet. It has been sewn in using a proven two layer offset shingle design, to give an even two layers of insulation throughout the sleeping bag with no sewn through cold spots. The Voyager uses a 30D DWR nylon shell, and a soft warm to touch 50D polyester pongee lining. The oversized neck-collar and hood-seal keeps drafts out, minimizing heat loss around the face. The bag uses an oversized zipper draft tube that hangs down to prevent heat loss along the side zip. Relaxed Mummy Convertible The Voyager relaxed mummy shape is cut with a larger hood, broader shoulders and large chest to provide a more comfortable sleeping bag while maintaining thermally efficiency. The foot box is anatomically shaped to accommodate the natural position your feet take when lying flat and relaxed. The addition of a full length side and foot zip allow for conversion from a traditional winter mummy shaped bag to a duvet offering the greatest versatility in a cold weather sleeping bag.