This extra large (12" x 18") and extra thick (1-1/4") extreme comfort mat is made of heavy, resilient, closed-cell foam rubber that provides plenty of space to move around. This super soft ergonomic mat will not absorb liquids, including oil and other petroleum products. It is also great for severe kneeling conditions such as cold hard steel, concrete, grating, and gravel surfaces. It is very easy to clean because of its closed-cell rubber nature; you can use soap, power wash, or even some harsher solvents if needed.