Galvanized units are made of corrosion resistant galvanized steel, with a removable polyethylene feed pan. Dimensions are the same as steel units. Aluminum provides all of the benefits of above steel units plus, the benefits of maintenance and corrosion free aluminum. Swing Out Combination Feeder .Aluminum Model CM 221 These items can ship to your residence FREE! CM221$310.00 View Installation Instructions CMI products toll free order and help line 1-800-335-1880. OHIO RESIDENTS will be charged Ohio Sales Tax unless we have a OHIO SALES TAX EXEMPTION FORM on file. The form is available at the link on the left side of this page.