The Castelli Feroce Midweight Long Sleeve Base Layer isn't your average base layer. The body of the shirt is constructed of medium weight seamless fabric, but has a lighter weight fabric under the bib upper. The sleeves are made of the heaviest weight seamless fabric. The result is something like a short sleeve base layer with attached arm warmers that have enough stretch to be pushed up when the heat rises. Designed for optimal temperature regulation under a short sleeve jersey--just ask the Cervelo Test Team guys.

• Polyester/Lycra blend
• Seamless construction
• Recommended for 45 - 65 degrees