Allows to set German armor in an immobile Hull Down position, increasing defenses. Received damage is only 75% from base penetration damage. For example Т-34 deals 120 penetration damage instead of 160. ISU-152 deals 180 penetration damage instead of 240. Good work in combination with Panzer IV Command Tank that gives -10% received damage: Т-34 deals 108 penetration damage instead of 120.