To use this Lassig short sleeve rashguard, simply put it on like a regular shirt before you go swimming. When wearing it, make sure it fits well to get the best UV protection. For maintenance, it's recommended to wash it in cold water with mild detergent. Avoid using bleach as it may damage the fabric and reduce the color fastness. After washing, hang it to dry. Remember, although the rashguard offers UV 50+ protection, it's still a good idea to use additional sunscreen for maximum protection when you're out in the sun for a long time.