Profile: CNI Mfg., Inc. is a manufacturer of multi containment boxes. Our product line includes EZ- lift manholes, snap tight fil-spil, gravity cover fil-spil, direct bury stand alone containment boxes, ground wire boxes, superior duct iron boxes, utility boxes and manholes. We also offer clamping device, adapter extensions, riser off sets, sump bladder with top hats, extractors & float valves, fil caps and adapters, island forms, vapor recovery caps and adapters.