16-Tile: item comes with 16 tiles in 4 colors and 24 end borders (6 boarders each color). each tile measures 12"x12"x0.4". each square = 1 square foot; total coverage 16 square feet (4' x 4' area)36-Tile: item comes with 36 tiles in 9 colors and 54 end borders (6 boarders each color). each tile measures 12"x12"x0.4". each square = 1 square foot; total coverage 36 square feet (6' x 6' area)Non-toxic, tested free of lead, bpa's and Phthalate; meet or exceed the US Regulated toy safety standards. Easy to clean with damp cloth & mild soap. Interlocking feature and lightweight make it very simple to assembleWith high density EVA foam, the 0.4'' thick premium mat comfortably cushions spine, hips, knees and elbows on hard floors. With double sided non-slip surfaces, BalanceFrom puzzle mat comes with an excellent slip resistant advantage to prevent injuriesAll genuine BalanceFrom products are covered by a 100% Balance From satisfaction guarantee and 2-year Balance From Warranty. Customer satisfaction is our highest priority