The FAMCO DM Damper Motor has a few variations available to fit specific needs. Choose 24 volt or 120 volt. An end switch or motor assembly is optional. The FAMCO DM Damper Motor come in either 1 RPM or 1/3 RPM. There is the option to order this Damper Motor open or closed. If you have any questions about the FAMCO DM Damper Motor and the options available, please refer to the FAQs above or feel free to contact us by phone or email.