4 Pack Vacuum Cleaner HEPA Filters for Cyclonic Series RO3753EA RO3731EA RO3786EA 1、1 2、2 3、3<br> Features:.<br> WBGT (wet-bulb globe temperature) became widespread for the use in workplaces and sports situation.<br> Using to control and monitor of physical activity in hot environment to limit the danger of heat related injuries.<br> Adjustable WBGT alarm setting, if the WBGT value over the alarm threshold, the buzzer will sound along with the flashing Display.<br> 3 ways to use, wear in your arm or mount it on the tripod, walls.<br> 4 Dangerous Level indicator display: Caution / Vigilance / Strict / Danger.<br> Specifications:<br> Color: black&white<br> Temp. range: 0-50℃/32-122℉<br> Temp. resolution: 0.1℃/0.1℉<br> Black Ball Temp. range: 0-80℃/32-176℉<br> Black Ball Temp. resolution: 0.1℃/0.1℉<br> Relative humidity range:<br> Relative humidity resolution: 0.1 RH<br> Heat Stroke Index(WBGT) range: 0-50℃/32-122℉<br> Heat Stroke Index(WBGT) resolution: 0.1℃/0.1℉<br> WBGT Temp.: IN(indoor), OUT(outdoor)<br> Operating condition: 0~50°C/32-122℉, 10~90% RH<br> Storage condition: -10~55°C/14-131℉, 10~90% RH<br> Powered by: 2 * 1.5V AAA(not included)<br> Item size: about 117 * 59 * 45mm<br> Packing List:<br> 1 * WBGT Meter<br> 1 * Arm Strap<br> 1 * English Instruction Manual<br> 1 * WBGT Meter<br> 1 * Arm Strap<br> 1 * English Instruction Manual