MODIFIED SOPRA G is an SBS-modified bitumen-coated base sheet for use as an anchor sheet for cold adhesive, heat welded or hot asphalt applied roof assemblies. MODIFIED SOPRA G is composed of a proprietary formulation of elastomeric styrene-butadiene-styrene (SBS) polymer modified bitumen and is reinforced with a high quality random glass fiber mat. The topside and underside are surfaced with fine mineral aggregate.