Sweat is nutritious to bacteria, after sweat was broken down by the bacteria, that's where the unpleasant smell comes from! SEK Antibacteria Finish is a mark attached to products that have undergone antibacterial and deodorant processing that suppresses the growth of odor-causing bacteria (bacteria such as Staphylococcus aureus) on fibers. Bacteria that use sweat and dirt as a nutrient source suppress the growth, showing a deodorizing effect and preventing the unpleasant odor of clothing such as socks and towels.