A popular tactical backpack mounts due to MOLLE interface to the back panel of an armor vest.
Due to compact external dimensions this backpack can significantly increase the useful load, so you can carry many various items in this backpack.
1-2 liter hydration pack may be put into this backpack, as well as a tablet, additional mags for your weapon, compact items of clothing and necessary equipment.
There are zippers on the right and left side at the bottom of the backpack that give access to the main compartment, needed items can be taken from the backpack out without removing the armor vest and without the help of other people.
On the outside of the pouch there is a Velcro panel for patches, which hides a small handbag (for example, for a mini first aid kit).
In the outer pocket you can place keys, a pack of bandages.
MOLLE webbing cells and compression straps on the outside of the backpack allow you to attach different equipment, for example, various pouches or fix the ground pad/insulating pad.