1 day to 3 day backpacks from brand like Warrior Assault, condor, Invader ggear and 101Inc. Perfect for your weekend events!
If you like to play milsim events then you definitely need a backpack!
A good backpack is definitely an addition to your tactical gear, especially if you participate in Milsim events. Milsim events often last a entire weekend and you will need to bring your own cookware, tent, sleeping bag, etc.