Buyers must prioritize CE and RoHS certification to ensure safety and environmental compliance for international markets. For medical or food-grade applications, look for NIST-traceable calibration certificates. Key specs include a wide temperature range (typically -50°C to 70°C), waterproof rating (IP65 or higher) for outdoor use, and dual-scale readings (Celsius/Fahrenheit). If purchasing for the EU market, ensure compliance with EN 12830 standards for temperature recorders used in the transport of chilled/frozen foods.