The N95 Mask Singapore would be the best bet as prevention from flu. However, facemasks could be relatively loose. These would be disposable masks approved by the Food and Drug Administration to be used as medical devices. Dentists, doctors, and nurses would often wear face masks while treating patients.
It would be pertinent to mention here that these masks would be preventing large droplets of bodily fluids containing virus from escaping through the mouth and the nose. Facemasks would also protect against sprays and splashes from others. It could be inclusive of coughs and sneezes. However, the downside would be these masks do not prevent the inhalation of airborne small contaminants.