Qingdao imported oxygen generator? What brands are there?

There are many oxygen generators on the market now, and the real imported ones are Yashi oxygen generators, which are noisy and expensive, and the instructions are all in English! In fact, many of them are imported brands, and it is still very practical to assemble the main parts in China! For example, Yingweikang, Aisong belong to 5L machine, Tortoise, Kaiya, Lu Shen, and easy oxygen source belong to 3L machine, all of which are very good! Life spans range from 20,000 to 35,000!