POND FILTER PAD 2" Thick 27" x 17" Koi Goldfish Media Floss by Aqua-Flo
You'll see it featured in every major Pond & Koi & Fish Care Magazine. Beige (COARSE DENSITY) Aqua-Flo Mat Filter Pad 27" x 17" x 2". Excellent surface area per sq. ft. with good adhesion of nitrifying bacteria.