Calvin Klein Performance Ck Perf Rtro Str Swt Ld91. Add a tinge of drama to your smart casual knitwear repertoire with this sweatshirt by Calvin Klein Performance. Crafted from a smooth fabric, this jumper features a round neckline, elasticated ribbed trims and hem for added comfort. Decked with colour-blocked print design, this long-sleeved profile is completed with the brand detailing. Pair this jumper with treggings and trainers for a stylish off-duty look.