Temperature range: -30 ℃ ~ + 70 ℃ (-22 ℉ ~ 158 ℉) Accuracy: ± 0.5 ℃ / 0.9 ℉ Resolution: 0.1 ℃ / ℉ Model: 25 days: PDF-25 (interval time: 5 minutes) Model: 50 days: PDF-50 (interval time: 10 minutes) Model: 99 days: PDF-99 (interval time: 20 minutes) Temperature units: ℃ / ℉ Delay Start Time: 20 minutes Storage time: 1 year Key functions: Start / Stop / Working status Display: LED (not started, recording, stop) Report Type: PDF format Interface: USB 2.0 Power Supply: 3.0V CR2032 lithium battery Operating System: WIN XP / 7/8 and MAC Protection: IP67