New. Undamaged. Flex U-Tube, 1211-120, -60 in wc to 60 in wc, 120 in Tube Lg. These portable analog manometers monitor static pressure in ducts and filters. They have a U-shaped, flexible tube that rolls up for storage and travel. These compact manometers are used for on-the-spot checks in HVAC and specific laboratory applications where monitoring the flow of air is necessary.