Some users reported they break the plastic ring that lock the filter in place. Here is a photo showing how to remove the lock ring without breaking it.
The trick is to press on the inside of the lock ring while lifting the tab at the outside. This technique effective “bending” the entire plastic parts. The ring will come out naturally without a lot of force pulling at the tab.
Recently the air pollution in Beijing has become a world wide topic. Just two weeks ago, Beijing has recorded the worst pollution days in 20 years. Air Quality Index shot through the roof and the government issue warning to ask the public stay at home. aqicn.info stands for Air-Quality-Index-China, which is a very useful site providing live data of air quality index in China and some parts of Asia.
If you are travelling to China, quickly check this site for the latest AQI report of your destination. Better to be prepared.
Some customers asked if our filters are effective again PM2.5, the very fine particles which are the key concern for many people. We sent our 96% to the highly reputable Nelson Labs for test. The result shows Totobobo 96% filter is able to cut down the number of particles from 10776 to 17, a filtration efficiency of 99.85%. Here is a test report available for download.