Gray Granite 1.5" — Heavy-Duty Stone for Deep Drainage & Backfill Also sold as #4 Stone (Crushed Granite) — the contractor spec name for the same material (AASHTO M43 / ASTM D448 No. 4).
Gray Granite 1.5" is the size that drainage installers, septic contractors, and excavators reach for when the project calls for serious water-moving