More than 20 states now require people to wear face coverings in public.

As more states make wearing face coverings in public mandatory, many wonder if masks with filters are more effective.

“Any cloth mask is going to protect others from whatever secretions you might inadvertently have,” Dr. Marty, a professor of infectious diseases at Florida International University told “Good Morning America.” “But if you add that filter, then you’re also adding a really good protection for yourself.”

Filters, which are essentially another layer that goes underneath a mask, can either be pre-sewn onto a mask or manually inserted via a pocket.

To help make the mask selection process a little easier, “GMA” spoke with Dr. Monica Gandhi, a professor of medicine at the University of California, San Francisco, and Dr. Marty, a professor of infectious disease at Florida International University. Both doctors shared their expert advice on filters and more.

Read on for some of their top tips to help you find the best mask for yourself.

What kind of mask should I wear?

Dr. Gandhi: Full masks protect you. It’s true that certain masks may filter out more or less viral particles, but cloth masks or surgical masks all filter out a majority of our particles. And how that protects you is, even if you’re exposed to disease, you’re very likely to get very mild or an asymptomatic infection. We don’t have to focus too much on what kind of masks. Just wear a mask.

What makes a good mask?

Dr. Marty: The ideal cloth masks that you really want to have is one that has three layers. So you have an inner layer, you’ve got the filter layer and you’ve got your outer layer. And you’ve got nice straps and then you’ve got some kind of a wire to help you adjust your nose. You put in a fresh filter and you just strap it on, adjust it for comfort and there you go.

Dr. Gandhi: Comfort is the name of the game. You want it to be actually fitting… the loops allow it to be tight fitting. And it doesn’t have to be that you should feel uncomfortable, but there’s nothing dangerous about wearing a mask.

Should I wear a mask with a filter?

Dr. Marty: Filters are going to give you increased protection from the mask. The wonderful thing about filters is that it isn’t just about the size of the filter, but they have a charge to them that helps collect the COVID-19 virus and keeps it from going beyond that filter layer.

What kind of filter should I use?

Dr. Marty: Any good filter or the same kind of quality filters that are found for sometimes venting devices are perfectly good. It’s not a very heavy material, it’s actually a nice, thin material, but it’s the way that the filter is made. It gives it that little electrostatic charge that’s so helpful for reducing the virus.

How often should I change or clean my filters?

Dr. Marty: I change out my filters frequently. You should replace that filter after the second or third time and wash it.

Dr. Gandhi: What a lot of people don’t like about the mask is if you wear stuff on your face and you eat and then it can get gross, so I absolutely recommend a cloth mask with the filter, if you choose to use a filter. And wash it out every night.