One of them is the pressure gauge to indicate the air pressure in the tank. The other pressure gauge is the pressure gauge that indicates the pressure setting at the regulator. This pressure is the amount of pressure received by the air tool . https://youtu.be/RafRvdMErTc Features: SMC similar High quality SMC type AF2000-02 ISO/CE Certification Selected from strict test F+R+L three units, body size 2000, port size 1/8", manual drain type, gauge inside, model no. Is AC2000-01M F. R. +L two units, body size 2000, port size 1/4", auto drain type, gauge outside, model no. Is AC2010-02D F+R, body size 3000, port size 3/8", manual drain type, gauge outside, model no. Is AW3000-03 Filter, body size 4000, port size 3/8", auto drain type, gauge inside, model no. Is AF4000-03DM Regulator, body size 4000, port size 1/2", model no. Is AR4000-04 Lubricator, body size 5000, port size 1", model no. Is AL5000-10 Specifications: Model AR2000 Fluid Air Port size G1/4″ Pressure range 0.05-0.85MPa Max. pressure 0.95MPa Proof pressure 1.5MPa Operating temperature 5-60°C Weight 0.20KG Material of Body Aluminum die-cast Package Includes: 1 x AR2000-02 Adjustable Air Regulator Pressure Gauge Reducing Valve Sign Facebook Instagram Pinterest