The Nike Pro Women's Long Sleeve Training Top is another popular synthetic base layer top on Amazon. Made with a blend of polyester and spandex, this top offers a comfortable and stretchy fit. It features Nike's Dri-FIT technology, which helps to wick away sweat and keep you dry during workouts. The long sleeves provide extra coverage and warmth, making it ideal for colder weather. The slim fit design allows for easy layering under other clothing. With its sleek design and high-quality performance, it's no surprise that this top is a favorite among women.