Small Backpack is a lightweight backpack that is unable to stack trade goods and has comparatively little space, but hinders combatants only slightly.
Small Backpacks have an inventory size of 3x3, making it the smallest of all backpacks. When equipped in the BACKPACK slot, this backpack adds a backpack inventory with a size of 8x8.
Can be bought commonly from Item Traders or sometimes looted from Wandering Traders or Slaver Caravan Guards. ru:Ранец