Office Depot K-Marble Foot Anti-Fatigue Mat, 24in. x 36in, Black/White, 064-0908-23 Marbleized PVC surface bonded to a 3/8" closed cell PVC sponge base Resilient foam provides anti-fatigue comfort. Since there is no glue used, mats are easy to clean and last longer for high-traffic areas. Great for hospital and laboratory environments or service counters.