The J-2000 Series Aero Type differential pressure gauges from Palmer Instruments feature a frictionless gauge movement and respond quickly to indicate low pressures, whether positive, negative (vacuum), or differential. Magnetic components of the spiral movement are replaced with a rubber film, a sensitive component in measuring pressure. This design resists shock, vibration, and over pressures without fluid fill. The result is no difficulty with evaporation, freezing, or leveling, which is found in other gauges. Featuring safe-slide pointers in green, yellow, and red, the gauges allows users to set visible reminders of safe, warning, and danger ranges. Combined with the red-tipped aluminum pointer, the gauges are easy to read, even from a distance. They come in units of psi, Pa, kPa, inches of water, millimeters of water, and centimeters of water.