Rubber-Cal "Eco-Sport" Interlocking Tiles, Blue 3/4 in. x 19.5 in. x 19.5 in. (132 sq.ft, 50 Pack) 03-208-LB-50PK - The Home Depot
American Floor Mats - 3/8 Inch Thick Warrior Heavy Duty Rubber Flooring - Interlocking Rubber Tiles 10% Blue Expansion Set - 4 Center Tiles - Amazon.com