Durable geotextile fabric top layer of Pig allows liquid to pass through to highly absorbent, oil-only polypropylene core that traps oil but lets rainwater evaporate. Nonpermeable polyethylene bottom layer keeps captured oil from leaching through to ground. Precut, ready-to-use 5 ft sq section soaks up 3 gal. Ten ft sq holds up to 12 gal. Reusable tarp resists UV and ties into place with brass corner grommets.