The K-Series mats are manufactured in 3 sizes, 3 in. x 3 in., 3 in. x 4 in., and 3 in. x 5 in. that will lock together to create virtually any size or configuration needed. The K-Series high performance design offers best in class anti-fatigue characteristics for commercial work stations. The K-Series molded cross bar surface assures safe footing while the multi-bar underside adds to comfort while enhancing drainage and cleanliness. The K-Series is 7/10 thick built in connectors on all sides. A key ingredient of the Rhino K-Series is tree-derived rubber, harvested from the Para rubber tree. It is beneficial to the environment, it is an ecologically sustainable and renewable resource, supporting the agricultural community and contributes to the maintenance of the global carbon balance in the atmosphere. Natural rubber is natures contribution to the elastomer field and offers the advantages of high resilience, high tensile and tear properties, and good flexing qualities at low temperatures. Color: Black.