Cast iron, concrete, composite rubber, or custom steel (set screws available) riser rings & grade rings. All standard sizes and styles are stock items. For raising your manhole covers to grade. Check individual items for traffic rating & ASTM data. Beware of poor quality imported imitations, always insist on made in USA. Please use the Contact Form or call us to request info & submittal sheets. 1-800-258-2278 Toll Free (972) 263-1360 DFW Local.