Castelli Core Seamless Base Layer Keeping You Warm In The Cool Introducing the Castelli Core Seamless Base Layer, a mild to warm-weather base layer that is ultra-breathable and lightweight. The polyester and polypropylene blended mesh fabric is extremely lightweight and breathable and helps to wick moisture away from your body. A seamless construction gives the base layer a stretchy fit and adds comfort. The sleeveless design means that it will fit under any jersey and also helps to cut the weight down, with the Core Seamless Base Layer weighing in at just 45 grams. Features Polyester and polypropylene blended fabricis lightweight breathable, moisture-wicking Seamless construction gives the exceptionally stretchy fit Weight: 45 grams SPECIFICATIONSMaterial Polyester and polypropylene Sleeve Length Sleeveless Closure Type None Fit Regular Sizing Size Small/ Medium Large /Extra Large2X Large Chest (in)36-37. 539-4143Waist (in)31-3334. 5-36. 538. 5 | Castelli | Core Seamless Base Layer Men's | Size Large/extra Large In White | Polyester