Use the Dwyer A-303 Portable Magnetic Static Pressure Tip with Manometers, Magnehelic Gages, Pressure Switches and other Controllers to pick up or sense static pressure drop across air filters and cooling coils, blower input and discharge pressures, etc. The angled tip has 4" insertion depth and fits through a ¼” hole. Model A-303 is for portable use, incorporating a magnetic mount for non-permanent installation. The Static Pressure Tip has four radially drilled .040" sensing holes.