EasyPulse Portable Oxygen Concentrator 3 Liter Comb Ultrasound Muscle Stim The deviation between the value 14272 The deviation between the value measured in the condition of man made light or indoor natural light and that of darkroom is less than ±1% you will finally be able to hear others in conversations❗Watch movies without blowing out the speakers warrants that the Portable Oxygen Concentrator POC (the Product) will be free of defects in workmanship and or material for the following period: Portable Oxygen Concentrator five (5) years from date of shipment * Battery 1 year from date of shipment Contents: EasyPulse POC concentrator Internal lithium ion battery Wall charger Car charger Comfortable carry bag with fully adjustable padded shoulder strap * All the features above are provided in a POC weighing 4