Installation Video: Pro-GHVFD - VFD Continuous duty worm gear jackshaft operator with emergency chain hoist March 31, 2021 21:00 Updated Related articles Installation Video: Pro-HB - Continuous duty belt drive jackshaft operator with brake Installation Video: Pro-GH - Continuous duty worm gear jackshaft operator with emergency chain hoist Webinar: An Introduction to Nice Commercial Door Operators Nice Commercial Operator Brochure Pro-H Instruction Manual - English