About Castelli UPF 50 Light Arm Sleeves
For maximum sun protection with minimal insulation. Castelli can officially only rate these warmers at UPF 50 , but in their laboratory tests they actually blocked 99.8 percent of damaging UV rays. They used a polyester base that is not only more effective than nylon at blocking UV rays but is also much better at keeping you dry, which means these arm sleeves are better in both cooler and warmer conditions. They’ve kept the construction very clean to eliminate seams that can rub, and they used their double-sided silicone elastic to make sure they stay in place. They fold up extremely small, so they’re great to stick in your pockets for your next big mountain day.

Features
Solare fabric keeps the chill off without causing overheating

UPF 50 protection

Polyester based for excellent moisture management

Double-side silicone elastic at top for excellent grip

About Castelli
Castelli are an Italian clothing manufacturer based in Fonzaso, Italy. In 1876 Vittore Gianni opened a clothing shop in Milan where he created clothing for AC Milan, Juventus, the Milan Ballet and cyclist Alfredo Binda. In 1935 Armando Castelli joined the business and four years later bought the company. He kept these high profile clients and continued making cycling clothing for riders including Fausto Coppi. In 1974 the scorpion logo was created and Castelli was born. Since then they've been at the forefront of innovation creating the first lycra shorts, coloured shorts and use of sublimation.