The bag (dimensions approximately 50 x 25 x 10–20 cm) is closed by tightening the drawstring opening which is secured with a waterproof protective collar which enables overpacking as well. The opening is covered with a flap which hugs the top of the backpack and is secured with straps. The generous length of the straps provides a lot of space under the flap for overpacking. The contents of the top compartment can be accessed quickly also from the right side through a vertical zipper that runs along the full height of the backpack.
Against the back inside the bag, there is a compartment the size of the whole back for the support frame of the backpack. The compartment is also ideal for carrying, for example, a hydration bladder or other flat items.
There is a holder for a Thermos flask inside the bag so that you can always find it from where it should be.
With the four compression straps on the sides of the backpack, the bag can be tightened compactly even if it is not full.
The flap of the bag has a flat zippered pocket for small items (dimensions approximately 20 x 20 cm).