Calvin Klein Performance Ck Perf Ls Sm Lgo Tp Ld91. Invite a sporty aesthetic to your work-to-weekend portfolio with this t-shirt by Calvin Klein Performance. Crafted from a smooth and stretchy material, this long-sleeved design features a round neckline for utmost comfort. Finished with the brands signature logo on the chest, this t-shirt is best teamed with joggers and trainers for a relaxed look.