Big Agnes Zirkel SL 20 Degree (2008) Sleeping Bag

Product Highlights

Updated for 2008! Lightweight and filled with high-performance goose down insulation, the Big Agnes Zirkel SL 20 Degree mummy sleeping bag is an ideal choice for 3-season backpacking. A generous cut makes the Zirkel SL 20 Degree less constrictive than most other brands of mummy bags.

The Zirkel SL 20 Degree is insulated with 800 fill goose down. Renowned for their compressible properties and efficiency in providing insulation, the feathers and fibers of down have an incredibly soft, comfortable feel and, despite advances in synthetic materials, continue to provide the best warmth-to-weight ratio of any insulation available. Though down fill is susceptible to the effects of moisture, losing much of its performance qualities when damp or wet, the ultra-light, high thread-count rip-stop nylon shell fabric of the Zirkel SL 20 Degree combats this risk by offering reliable water repellency.

In a traditional sleeping system, the bag lies on top of a sleeping pad. In this configuration, many people find themselves rolling off the pad at night. Plus, the insulation on the bottom of the bag is compressed by the sleeper's weight. Once compressed, the fill loses most of its insulating properties. The Big Agnes Sleep System is different, joining the bag and pad together. The pad slides into a sleeve on the bottom side of the bag, supplying insulation to the bottom of the bag while the top 2/3 of the bag is insulated like a traditional sleeping bag. This design provides a secure foundation so you can roll, twist and turn freely during the night without ever rolling off your pad. It also prevents the bag from twisting and engulfing you in an uncomfortable mess. Big Agnes uses this system throughout their entire line of sleeping bags.

The Zirkel SL 20 Degree is available in Reg (fits up to 5'10") and Long (fits up to 6'6") lengths. Once you match your bag with a mummy-shaped sleeping pad of the appropriate dimensions (20" x 72" for Reg and 20" x 78" for Long), spending a night in the Zirkel SL 20 Degree is both warm and comfortable.

A number of performance features equip the Zirkel SL 20 Degree for efficient insulation. A contoured, insulated hood keeps your head warm and a no-draft collar keeps cold air from creeping in the top of the bag and reaching the interior of the Zirkel SL 20 Degree. A full-length draft tube sewn behind the zipper further ensures that cold air remains outside of the bag. A no-draft wedge protects the connection between the bag and the pad, so that cold air doesn't sneak in between the two. A built-in pillow pocket holds clothes or a Big Agnes Air Core Pillow (sold separately), providing a comfortable resting place for your head and neck.

For your convenience, the Big Agnes Zirkel SL 20 Degree is available in your choice of Right and Left zippers. A recycled mesh storage sack and nylon stuff sack are included with each Zirkel SL 20 Degree.