• Measuring range: -20 to +60 °C (testo 405i + testo 410i + testo 605i)
• Accuracy: 

1.  ±0.5 °C (testo 405i + testo 410i)
2.  ±0.8 °C (-20 to 0 °C) (testo 605i)
3.  ±0.5 °C (0 to +60 °C) (testo 605i)

• Resolution: 0.1 °C (testo 405i + testo 410i + testo 605i)

• Measuring range: -30 to +250 °C
• Accuracy:

1.  ±1.5 °C or ±1.5 % of mv (0 to +250 °C)
2.  ±2 °C (-20 to -0.1 °C)
3.  ±2.5 °C (-30 to -20.1 °C)

• Resolution: 0.1 °C

• Measuring range: 0 to 100 %RH
• Accuracy: 5 to 80 %RH: ±(1.8 %RH + 3 % of mv) at +25 °C
• Resolution: 0.1 %RH

• Measuring range: 0 to 30 m/s
• Accuracy:

1.  ±(0.1 m/s + 5 % of mv) (0 to 2 m/s)
2.  ±(0.3 m/s + 5 % of mv) (2 to 15 m/s)

• Resolution: 0.01 m/s

Dimensions:

• 200 x 30 x 41 mm (testo 405i)
• 140 x 36 x 25 mm (testo 805i)
• 154 x 43 x 21 mm (testo 410i)
• 243 x 30 x 24 mm (testo 605i)

Operating temperature

• -20 to +50 °C (testo 405i + testo 410i + testo 605i)
• -10 to +50 °C (testo 805i)

1. System requirements: requires Android 4.3 or newer; requires mobile end device with Bluetooth 4.0
2. Battery type: 3 micro batteries AAA (per Smart Probe)
3. Battery life: 15 h (testo 405i), 200 h (testo 410i), 250 h (testo 605i), 30 h (testo 805i)
4. Storage temperature: -20 to +60 °C
5. Length probe shaft: extendable to 400 mm (testo 405i); 100 mm (testo 605i)
6. Diameter vane: 40 mm (testo 410i)