1PC Upgraded Oxygen Humidifier Bottle for 5L or Less Concentrators, Universal Fit for Philips,Yuwell, MICITECH，Spiral-Type Interface, Metal Check Valve with Backflow Prevention & Fire Isolation

Upgraded Safety with Metal Check Valve: Features a 6 PSI pressure relief and metal check valve to prevent water/gas backflow and reduce fire spread risk, designed to meet UL2208 and EN ISO8359 safety standards.
Ideal for CPAP & Oxygen Concentrator Users: Perfect for CPAP users with oxygen concentrators; the metal check valve prevents water/oxygen backflow into CPAP machines, ensuring air flows only when open for effective therapy.
Enhanced Safety for Oxygen Therapy: With rising fire safety concerns in oxygen concentrator use, our upgraded metal check valve minimizes flame spread risk along tubing, prioritizing your safety.
Universal Fit for 5L or Less Concentrators: Direct-plug interface fits Yuwell, Philips, and most home/portable oxygen concentrators up to 5L, a reliable, cost-effective OEM alternative; check main image for compatibility.
Portable & Easy to Maintain: Lightweight PP plastic with clear, etched water level markings and a non-scaling, easy-to-clean design ensures precise humidification and lasting performance.