The Arnold Company is the number one manufacturer of Hopper Gate Openers in the United States. As home of the Door Demon® Hopper Gate Opener, we also offer custom designed Hopper Gate and Boxcar Openers to meet the specific needs of your working environment. The Arnold Company takes pride in its product selection, product quality, and personalized customer service. We offer our customers affordable, practical solutions to their Hopper Gate and Boxcar Opener needs, and we stand behind our products.