The differences between the 3/8" Sport-Lock Rubber Tiles and our 3/8" Rubber Gym Tiles is that the Rubber Gym Tiles are a vulcanized tile. That means they are non-porous and are denser than the Sport-Lock Tiles. This gives the Rubber Gym Tiles a leg up when it comes to dropping heavy weights. The Rubber Gym Tiles also are a different size compared to the Sport-Loc Rubber Tiles. The Sport-Lock Tiles are 3' x 3' while the Rubber Gym Tiles are 2' x 2' and 4' x 4'. The other main difference is the surface of the tiles. The Sport-Lock Tiles have a flat surface that helps to give you a more consistent look whereas the Rubber Gym Tiles have a textured top which can give you a very inconsistent look. Both come in corner, border, and center tiles, but the Sport-Lock Tiles have an added feature having two removable border pieces. This means any tile can be made into a corner, border, or center tile, whereas the Rubber Gym Tiles would need to be ordered in that manner. The last difference is that the Rubber Gym Tiles can come beveled. This could be beneficial if you are trying to match up the tiles to another flooring surface or at entryways.