Lightweight, durable, and easy-to-cut. Matala filter media is available in two densities. Medium (green) or High (blue). Both densities can be used for either mechanical or biological filtration. Matala offers one of the highest surface areas of all filtration products on the market. Made with a special coating giving it a smooth surface allowing water to pass easily through it without channeling. Easy to clean - Extremely durable & Long lasting. Each mat measures 39.5" L x 24" W x 1.5" Thick. Each mat filters approximately 500 gallons.