Slats with gaps between them let water drain straight through instead of pooling under your feet, which is the difference between this mat and a solid rubber sheet that traps damp. It is made from HIPS rather than wood or bamboo, so it will not warp, rot or grow mold in a wet room, and 304 stainless steel screws hold the 23.5 by 19 by 2 inch platform together at a rated 330 lbs. Rubber foot pads grip the tub floor and the textured surface stays secure underfoot; rounded edges mean no sharp corners to catch a toe. At 10 lbs it lifts out easily for cleaning. Use it in a shower, a bathtub, by a pool or at a back door.