HD9908TBARO, unlike the other models, is equipped with a display showing the pressure measurements, an analog output 0…20 mA, 4…20 mA, 0…1 V and 0…5 V (0…10 V on request) configurable by the customer and with an ON/OFF relay output with programmable alarm threshold. HD9908TBARO requires a 24 Vac (or 220 Vac on request) power supply