Polo neck
(重定向自Turtleneck Sweater)
A polo neck, roll-neck (UK) or turtleneck (US, Canada) or skivvy (Australia, New Zealand) is a garment—usually a sweater—with a close-fitting, round, and high collar that folds over and covers the neck. It can also refer to type of neckline, the style of collar itself, or be used as an adjective ("polo necked").