Features:<br> Professional for testing the oxygen content of the air, with 0-25% oxygen content detection range.<br> Adopts with good quality electrochemical sensor, the O2 meter respond quickly yet has high precision.<br> 3.7V 1000mAh large capacity rechargeable lithium battery has long standby time and low power consumption.<br> 2.7-inch large LCD display screen, and the green backlight for clearly reading the measured data.<br> Compact portable size with ergonomic design is easy to use, high quality rubber buttons has comfortable hand feel during operation.<br> Sound and light dual-alarm when the measured result exceed the preset alarm value.<br> The O2 tester has stable performance and high accuracy that suitable for home use, agriculture, chemical industry, etc.<br> Specifications:<br> Material: ABS<br> Voltage: AC100-240V, 50/60Hz<br> Output: DC5V±5%, 1000±50mA<br> Measuring Range: 0~25%<br> Resolution: 0.1%<br> Temperature: -10~50℃<br> Resolution: 0.1℃<br> Working Humidity: 0~95%RH<br> Power Supply: 1 * 3.7V, 1000mAh rechargeable li-ion battery<br> Screen Size: 4.4 * 5.3cm / 1.73 * 2.08in<br> Storage Box Size: 23 * 20.5 * 5cm / 9.06 * 8.07 * 1.97in<br> Item Size: 18.3 * 6.5 * 3cm / 7.20 * 2.56 * 1.18in<br> Item Weight: 245g / 8.64oz<br> Package Weight: 743g / 26.21oz<br> Package Size: 25.5 * 21 * 5.7cm / 10.04 * 8.27 * 2.24in<br> Package List:<br> 1 * Detector<br> 1 * USB Cable<br> 1 * Storage Box<br> 1 * Manual (English)