Stain Block Elite is a state of the art, water and stain resistant, penetrating fluoropolymer impregnating sealer. It has been specifically designed for porous to dense concrete, brick, natural and manufactured stone surfaces. When dry it is virtually invisible, leaving the surface with its original appearance and breathability. It resists oil and grease stains, rust stains, moss, mildew and spalling problems associated with freeze/thaw cycles. Stain Block Elite provides superior protection against moisture penetration, thereby reducing the formation of efflorescence.