Oxygen crisis is going on in the hospitals of other states including Delhi amid the second wave of corona across the country.Efforts are being made from every level for oxygen supply.The relatives of patients are seen arranging oxygen cylinders from their level even in the midst of low oxygen in hospitals.But how long is it possible that one should wander from rate to door to get the oxygen cylinder filled by himself.In such a situation, oxygen concentrators are a better option for corona patients with mild and moderate symptoms.1. Philips Everflo Oxygen Concentrator: This machine, priced at Rs 50,000, weighs about 14 kg.It has the capacity to deliver up to 5 liters of airflow with 93-96 per cent accuracy.Its maintenance is easy.2. BPL OXY 5 NEO Oxygen Concentrator: The price of this machine with airflow up to 5 liters with 93 percent accuracy is around Rs 50,000 in India.3. Dedakj De Oxygen Concentrator: The price of this series concentrator falls between Rs 45 to 60 thousand. It has the capacity to provide airflow up to 6-8 liters with 9 percent accuracy.