V4 is a thicker nanocoating that offers the same protection as V1, V2, and V3 but protects at a higher industrial grade level. V4 is highly recommended for devices in corrosive environments as it contains a strong physical and chemical barrier against corrosion substances as it is formulated with a proprietary blend of organosilicon chemistry. Electronics coated with V4 have passed tests longer than 400 hours in a salt fog chamber per ASTM B117.