Available in 24", 36" and 48" models, the GrowerSELECT® Curtain Machines accurately control ventilation curtains, sidewall inlets and tunnel doors. Innovative shaft guides and load nut provide exceptionally smooth operation and enhanced reliability. Dual limit switches allow unit to be "locked-out" to prevent damage in the event of primary limit switch failure. Local control switches inside the durable galvanized housing allow accurate setting of operation limits while precision cutouts provide easy removal of the ACME screw and block should removal ever be required. Upgrade to a GrowerSELECT® curtain machine for your operation and experience the right kind of sticker shock!