Ideal set for climate professionals focusing on volumetric flow measurement. You will receive the universal climate measuring device testo 400 with intuitive measurement menus, a vane probe head (Ø 16 mm), a vane probe head (Ø 100 mm), and a highly precise humidity-temperature probe head – all three can be attached to the included Bluetooth handle. For measurements at ceiling outlets, simply combine the 100 mm vane probe with the telescope (extendable up to 1.0 m) and the 90° angle. Please do not use the probe in dew-forming atmospheres. For continuous use in high humidity areas, please contact Testo service.