A versatile, high-performance patching compound formulated to stop running water through deep cracks, holes and imperfections in concrete and masonry surfaces. It creates a watertight seal in 3-5 minutes, even while water is flowing. It works both above and below ground level. Also great as fast-setting anchoring cement to permanently anchor fence and railing posts, bolts, machinery and fixtures into concrete and masonry surfaces. Interior / exterior use.