The Under Armour Women's ColdGear Armour Compression Mock is a top-rated base layer top for women's tennis on Amazon. It is designed to keep you warm and comfortable during cold weather matches. The compression fit provides a snug and supportive feel, while the ColdGear fabric traps heat and wicks away sweat to keep you dry. The mock neck design offers extra coverage and protection against the elements. With its top ratings and positive reviews, this base layer top is a popular choice among women tennis players.