On its own, this is an efficient 2-3 season bag useable from April to September.
Combined with the 4S Inner, this can be used all year round in sheltered places. With the further addition of the Thermaliner, either between the Outer and Inner or inside the Inner as protection against dirt, you have a full 4 Season system, for comfort all year round.

- Heavy duty, three quarter length front zip
- Zipped hood closure
- Non-locking zips
- Internal toggles for attaching to an Inner or Thermaliner
- Stuff sack with compression spider
- Easy to wash (although a launderette is recommended)