Specifications: Temperature Range: -121°F ~104°F, -85°C ~40°C All accuracy: +/-1°F/ + 0.5°C Resolution : 0.01°F/ 0.01°C Data Capacity: 7200 group Download speed: less than 5 seconds Storage life: more than 5 years Start: Press the start button three seconds Battery: 3.6V, 0.4Ah cryogenic industrial batteries. Shockproof performance: Withstands 3-foot (1 meter) drop to hard surface Operating instructions: the red indicator flashes after starting Selection Guide: DI-05: Sampling interval 1 minute, record up to 5 days DI-25: Sampling interval 5 minutes, record up to 25 days DI-50: Sampling interval 10 minutes, record up to 50 days DI-99: Sampling interval 20 minutes, record up to 99 days