Alpha Direct 4004 Overbag


An overbag built from one layer of Alpha Direct 4004. Alpha Direct is extremely breathable without a wind blocking layer so this overbag should only be used in still air. In still air it can provide a substantial boost in warmth that can push the dew point out of your down system while also catching outside moisture. If moisture management is not a concern, this overbag can also be used as a comfortable inner bag liner to add warmth and separate your skin from your sleep system’s shell fabric.

See home page for the made-to-order lead time.

Comes in 58″ wide x 80″ long unless specified otherwise and weighs approximately 9oz. There is a top shockcord and a footbox drawcord.

Coyote Brown
Castor Grey
Rhubarb Red
If you want to custom fine tune your fit, write in the dimensions you would like here in this format Width x Length. You can take the loose outside measurement of the footbox area of your down system and enter that as the width. Take the loose outside measurement of the length and enter this as the Length. Do not compress your down when taking these measurements. Do not exceed 58" in width or 90" Length.
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The Alpha Direct Overbag is a synthetic overbag that can go over a down sleeping bag. Using a synthetic overbag is sometimes a necessary way to keep your down dry in really cold, or really wet environments. In really cold environments the moisture that your body puts out in the night will travel through your sleep system and condense wherever the dew point is, which is typically inside of your down loft somewhere. Adding an Alpha Direct Overbag to the outside pushes that dew point out of the down and into the Alpha Direct 4004 fabric. From here you can remove the moisture from your down and pack it away dry. The moist overbag can either be dried during the day, or left moist and packed separately. If the moist overbag is reinstalled over the down bag the next night your body temperature will continue to push the dew point into the Alpha Direct fabric and the down bag will continue to stay dry. The overbag will continue to accumulate moisture and will need to be dealt with at some point, but Alpha Direct is remarkably good at dealing with moisture. It does not lose loft and dries very fast.

In really moist environments above freezing, the moisture is likely to come from the outside. An Alpha Direct Overbag is not waterproof, but it can catch light moisture that comes in the form of condensation or contact with wet tent/tarp walls or whatever. This moisture will soak into the overbag and need to be dealt with at some point, but it creates a barrier between the moisture and your down system.

It also doubles as an insulated poncho. This can allow you to either leave a jacket at home, or at least bring lighter insulating layers. This can often fit over a small backpack too, keeping things somewhat warm back there.

Weight .3 kg


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