The Actis Boost'R Hybrid Reflective Breather Membrane 6.7 x 1.5m x 35mm (L x W x T) is a thin mutli-foil insulation with a built-in breather membrane function and an exceptional thermal performance. It is used on the cold side of the building fabric in roofs and walls. Boost'R Hybrid provides dual properties within a single product: a breathable membrane and insulation, allowing a reduction in the number of installation steps whilst reducing the thickness of the main insulation to achieve the same required U-value. It can be used in conjunction with any type of insulation.