Vostermans Variable Speed Drive 10 Amp with Manual Override

            The Vostermans Variable Speed Drive 10 Amp with Manual Override             offers precise control for your ventilation system. It features a             manual speed selector dial and an easily accessible toggle switch             for switching between manual and automatic modes. Available in three             models with 0-10 volt or 4-20 mA input signals, it also includes an             internal minimum speed adjustment for continuous operation at             minimum speed.