With more than 4,000 five-star reviews from shoppers who claim the mask is lightweight, easy to breathe in, well-fitting, and resistant to glasses fog, I was intrigued but skeptical. I’d been burned by supposedly breathable masks before, leading to uncomfortable outdoor workouts I had to cut short. Some masks were too big and fell down my face, while others were so lightweight that they stuck to my nose and mouth so much that I couldn’t breathe properly unless I walked at an easy pace. Space Mask’s nanotech mask does nothing of the sort. Despite its triple-layer construction, the mask is as breathable as advertised, and I certainly put it to the test. I wore it on an 11-mile bike ride through Manhattan on a sunny August day and practically forgot I had it on. Later, I wore it on my regular 4-mile running route through Central Park, and not once did I have the overwhelming urge to rip it off. Even though my heart rate was elevated, I could breathe well through the mask, and it stayed put the entire time. The mask features a mesh inner layer that feels soft and wicks moisture to keep you cool and dry, an antibacterial polyester filter in the middle, and a woven UV-protective, antibacterial outer layer. Its naturally protective fabric is treated with a nano-antimicrobial to prevent micro-organisms from growing on its surface. The result is a mask that feels smooth to the touch and fits comfortably thanks to adjustable cotton elastic straps, a moldable nose bridge, and ergonomic nose and cheek contouring. Space Mask has released multiple face mask iterations since launching in February of this year, so be sure to select the newest launch (the 3.0 model) for all the features I described. You can order the masks in small or large sizes; I went for the small, but there’s a size guide to help you determine which is best for you. They’re available to order one at a time or in packs of three, six, or even 50 if you’re shopping in bulk. You’ll have to hurry to get your hands on the style you want. Certain colors of the mask have sold out multiple times over the last few months. At one point, there were as many as 2,000 backorders! So head to Space Mask today to order the comfiest mask I’ve found so far, whether you’re looking for a face mask to wear while running errands or running a 5K. To buy: From $19; shopspacemask.com.