The 2002 Dwyer differential pressure gauge gage relies on simple, frictionless Dwyer gage movement to quickly indicate air or noncorrosive gas pressures--either positive, negative (vacuum) or differential. The patented design resists shock, vibration, over-pressures and is weatherproof to IP67. Applications for the Dwyer 2002 gage include: Filter Monitoring, Air Velocity with a Pitot Tube, lower Vacuum Monitoring, Fan Pressure Indication, Duct, Room or Building Pressures, Clean Room Positive Pressure Indication. FEATURES include: Easy to read gage through undistorted plastic face permits viewing from far away; Patented design provides quick response to pressure changes means no delay in assessing critical situations; Durable and rugged housing and high-quality components combine to provide longs ervice life and minimized down-time; Bezel provides flange for flush mounting in panel; Clear plastic face is highly resistant to breakage. Provides undistorted viewing of pointer and scale; Precision litho-printed scale is accurate and easy to read; Red tipped pointer of heat-treated aluminum tubing is easy to see. It is rigidly mounted on the helix shaft; Pointer stops of molded rubber prevent pointer over-travel without damage; "Wishbone" assembly provides mounting for helix, helix bearings and pointer shaft; Jeweled bearings are shock-resistant mounted, providing virtually friction-free motion for helix. Motion damped with high viscosity silicone fluid; Zero adjustment screw is conveniently located in the plastic cover and is accessible without removing the cover. Helix is precision made from an alloy of high magnetic permeability. Die cast aluminum case is precision made and iridite-dipped to withstand 168-hour salt spray corrosion test. Exterior finished in baked dark gray hammerloid.