What does the protective kit provision do in World of Tanks Blitz?

In World of Tanks Blitz, the protective kit provision provides 15% extra protection to your crew against injuries.
It also increases module repair speed by 10%, increases fire protection by 20% in the case of engine (not fuel tank) fires and and increases the durability of the ammo rack and fuel tank by 10%.

It is mostly useful on tanks with weaker armour.