Deep-penetrating and breathable, Certi-Vex Penseal 244 O/W high-solids, VOC solvent-based clear silane sealer combines hydrophobic and oleophobic technologies to stop the intrusion of water, oil, grease, salts, deicer chemicals, acid rain, and food staining from concrete and masonry surfaces. This prevents efflorescence, mildew, corrosion, scaling, spalling, surface erosion, and other costly damage to hard surfaces. Vexcon Chemicals Inc. WOC Booth S11545