This sun cream has been developed to protect exposed skin from the increased intensity of the suns harmful rays at altitude. Ideal as a mountain sun cream, this unique formula combines advanced UVB/UVA filtration with added vitamin E and B to protect your skin from the sun and long term skin damage. Apply liberally over dry skin 30 minutes before sun exposure. One application lasts for up to 6 hours. Reapply every 2 hours at high altitude, areas of increased humidity, after swimming or using a towel.