Protan PRO Primer UNI is a single-component, polyurethane-based primer used for all types of surfaces for the application of PRO Liquid D polyurethane liquid membranes. A universal primer with a wide range of applications: glass, metals, concrete, ceramics, OSB, EPDM, bituminous felts. Smooth absorbent and non-absorbent surfaces. Also used as an impregnation.