Grabs the upper arm comfortably yet firmly with an elastic band located at the top of the sleeve. Change your entire wardrobe for less than the price of a single shirt! Sleevies an original Kosher Casual design enables any top to be converted to a 3-4 sleeve shirt. Each package contains 2 sleeves. 90% Natural Viscose / 10% spandex soft and breathable stretch knit fabric. See size chart in images for best fit. Elastic is approximate because it is stretchy. Imported. Machine was cold.