testo 435-4 multi-function measuring instrument with built-in differential pressure measurement for air conditioning, ventilation and Indoor Air Quality, with data memory, PC software and USB data transfer cable, includes battery and calibration protocol

testo 435-3, multi-functional measuring instrument with built-in differential pressure measurement for air conditioning, ventilation and Indoor Air Quality, with battery and calibration protocol

testo 435-2 multi-function measuring instrument for air conditioning, ventilation and Indoor Air Quality with data memory, PC software and USB data transfer cable, includes battery and calibration protocol