Pertex 5 Shell with 'AquaTherm' pile lining. A very compact and light summer bag. Ideal for cycle camping, mountain marathons and backpacking. Very useful as an outer for upgrading conventional sleeping bags. Hooded, with a heavy duty three quarter length front zip. Supplied in stuff sack but compacts so well it does not need a compression spider. Sizes: S, M, L, XL. Colours: Nato Green, Royal Blue. Weight: 824g Packed Size: 28 x 23cm   'AquaTherm Extreme' pile only. On its own this is only suitable for Bothies or camping between May and August. Add the "Thermaliner" as a shell and it makes a 2/3 season Bag. Used as an inner bag with the 4S Outer this completes a full 4 Season bag. Hooded, it has a three quarter front zip and tape loops for attachment to an Outer or Thermaliner. Supplied in stuff sack. Sizes: S, M, L, XL. Colours: Black, Nato Green. Weight: 1198g Packed Size: 34 x 23cm   Pertex 5 Shell only. As well as being an integral part of the "4S System", the "Thermaliner" is often used as an easily washed liner or outer cover for conventional sleeping bags. It will increase the performance of most bags by half a season. Hooded, the liner has a three quarter front zip, and tape loops on the outside with toggles on the inside, for attachment to the "4S Outer" and "Inner" respectively. Sizes: S, M, L, XL. Colours: Nato Green, Royal Blue. Weight: 230g Packed Size: 8 x 15cm