Plastic composite. XPotential Products will not twist, splinter, rot or decay. In comparison to wood, XPotential Products possess a much greater compressive strength. Flexural strength is in the range of 1/2 to 2/3 that of wood. Harsh elements, severe temperatures, submersion in fresh or salt water and freeze / thaw cycles have little effect on our products. They will not suffer a reduction in structural integrity due to insect damage, termites, rodents, road salt, and periodic contamination with oil, gasoline and many corrosive chemicals.