WINTACT WT8821 Oxygen Detector Independent Oxygen Gas Sensor Warning-up High Sensitive Poisoning Alarm Detector

specification 1. Measurement range: 0~25% VOL 2. Maximum overload: 30% oxygen 3. Response time: <15 seconds 4. Sensor type: electromagnetic O2 sensor 5. Use ambient humidity: 15~90% RH 6. Power: 3X1.5VAA battery Package Included 1 x Oxgen gas detector (without battery) 1 x manual