Replacement Aeration StonesAir stones can become clogged with mineral deposits which hamper their performance. Keep your portable aerator operating at peak efficiency by replacing the air stone on a regular basis.Features:. High Output Air Stones quality aeration. Premium Air Hose- includes 30 of tough non-kink air hose. Includes aerator hose & 2 stones. 7" x 5.5" x 1.5"