Interlocking 3/4" Thick Anti-fatigue Rubber Mat, Heavy-Duty, De-Flex®, Model 570NR. They have rubber domes on the bottom, so they can function as Anti-fatigue mats as well. Diamond pattern on the top.
The 24 tiles were arranged in a 4 x 6 configuration to cover an area of 6 x 9 feet. There was also a 25th tile that was cut into peices to cover some additional gaps and some of the tiles are going to have the interlocking parts cut off. Comes with ~6 feet of 571 ramps as well.
Price is firm. If the ad is up, the lot is available. Will not sell items separately.