By completing all five stages, you will gain access to new specialisations and their signature weapons in the SHD arsenal.
If you have the Year 1 Pass, you will instantly unlock the Gunner, Technician and Firewall specialisations.
You can still take on the Special Field Research, but as you progress through the stages you will unlock additional exclusive cosmetic rewards:
Gunner: the Fisticuffs and Front Flex emotes, Charcoal and Detritus gear dyes, Rosethorn and Pineapple weapon skins, the Gunner mask and the Gunner specialization uniform.
Firewall: Firewall safety mask, safety helmet, shirt and pants, Caldera and Basalt weapon skin, Lava Lake and Tremor gear dye and Mundane Signature weapon skin.