•  1-3 Liters – Great for personal items, first aid supplies or as an extra layer of protection for electronics and batteries.
  
•  4-5-Liters – A good size for storing a sleeved or sleeveless cooling vest, jacket and pant liners or base layers.
  
•  8-10 Liters – Handy for storing clothing for an overnight trip or an ultra-light sleeping bag.
  
•  11-20 Liters – Good for storing a medium sized synthetic sleeping bag or multiple synthetic clothing items.
  
•  35 Liters – Large enough for a heavy weight sleeping bag.
  
•  55-65 Liters – A “protect everything size” great for multi-day trips. Easy to strap to a rear luggage rack or line your panniers for a convenient, removable, water proof, system. Just grab and go.