Fume cupboard probe, fixed cable, Probe Diameter 0.39 in, Probe Type Hot Wire, Relative Humidity Accuracy Not Applicable, Features Intelligent Calibration Concept, plug into testo 400, Includes Calibration Protocol, Maximum Hot Wire Probe Length 55.1 in, Minimum Hot Wire Probe Length 5.9 in, Minimum Relative Humidity Measured Not Applicable, Minimum Temperature Measured 32 Degrees F, Minimum Velocity Measured 0 fpm, Air Velocity Resolution 0.01 fpm