A mat unit is formed from at least two layers ultrasonically welded together. Each layer is individually formed from non-vinyl nontoxic thermoplastic elastomer (TPE) material. In ultrasonically joining the two layers together, there is no need to use additional materials, such as adhesive (i.e., chemical attachment) or stitched thread (i.e., mechanical attachment) to form the joint/weld point. Once formed from the two layers, the mat unit has four quadrants and a plurality of longitudinal ribs integrally formed in the first layer positioned in the first and third quadrants, and a plurality of transverse ribs integrally formed in the first layer positioned in the second and fourth quadrants. Additionally, there are a plurality of longitudinal ribs integrally formed in the second layer positioned in the second and fourth quadrants, and a plurality of transverse ribs integrally formed in the second layer positioned in the first and third quadrants.