Drylok 20913 Masonry Waterproofer, Milky White, 1 gal, Can, Pack of 2Waterproof interior, exterior, above or below grade walls. Unlike ordinary paint that simply adheres to a surface and can be forced off by incoming water pressure, DRYLOK floor and wall masonry waterproofer actually penetrates the pores in that surface, bonding to the masonry and creating an impenetrable barrier. Unit: GAL UPC: 079941209131 Model Number: 20913