Long Sleeve Mock � The Sierra Swirl Long Sleeve Mock is the perfect layering piece for any outdoor activity for multiple reasons. The jersey fabric is built for performance while our limited-edition Sierra Swirl print is one of a kind. The purple mist sleeves and zipper harmonize magically with the pattern. This long sleeve athleisure item has long back body darts which will slim your figure and a scoop hem which will prevent any bunch up during your backswing. UPF30 Protection.