This engineered maple is 3/4″ thick and exceptionally-milled by one of the best flooring producers on earth. No knots are allowed in this grade, but some slight color variation is. It’s one of our very favorite floors and a tremendous value at this price! The finish is water-based urethane with ground ceramic in the topcoat for extra durability. The finish carries a 35-year residential warranty. This flooring is suitable for at-grade, above-grade, & below-grade installations. It can be nailed, glued, or floated.