This casual long sleeve army-style shirt for men is a great addition to your wardrobe. To wear it, simply put it on like any other shirt. When choosing a size, remember to check the size chart carefully as different suppliers may have different sizing. If you usually wear a size S in US sizes, it's better to choose a size L in Asian sizes. As for maintenance, you can machine wash it in cold water with like colors. Avoid using bleach as it may damage the fabric. Hang it to dry to keep its shape. This shirt is made of a blend of polyester and spandex, which makes it comfortable and stretchy. You can wear it for casual outings or even for parties. Enjoy your new shirt!