This is the Swiss Army M90 Assualt Pack, or Sac de Combat 90.
This pack is made of a rubberised material, it' water resistant.
40 Liter Pack
Produced by Hugo Ruegg SG in 1992, to name one of the producers
Has several attachment points.
Olive Drab colour
Issued and in very good condition.
The Combat Pouches for the Combat Web Belt system can be attached to the attachment points, adding more outer pockets for canteens and other gear.