Amazon.com: Aluminum Oxide. $25 & above. Get It by Tomorrow. Amazon.com Go to product viewer dialog for this item.

: Ideal for business-grade brown aluminum oxide in specific mesh sizes (e.g., 100 mesh) for heavy-duty industrial use.

Aluminum oxide is widely available from hardware stores, industrial suppliers, and specialized online retailers, with its availability largely determined by your intended use (e.g., sandblasting, polishing, or industrial applications).