Eclipse sun sleeves are super soft and durable. They wick moisture away from the skin to keep you cool in the hot sun and provide insulating warmth in the morning chill. The sleeves are designed to cover the back of the hands, which are particularly vulnerable to sun exposure. They stay up your arm by virtue of the spandex component (87% Cocona/13% spandex) so even a vigorous golf swing won"t cause them to sag. The stretchy fabric allows a lot of latitude in sizing, so if your style is active, consider a smaller size for a more snug fit.