Castelli womens imprevisto jerseyimprevisto is the first jersey that brings castellis nanotechnology water repellent treatment to a fully breathable jersey fabric in dry conditions you have all the air flow and moisture wicking of your favourite jersey yet the nanotechnology treatment repels water in order to keep you dry should you get caught out in light rain or from light spray on wet roads as there is no membrane the jersey is not waterproof and castelli dont make any claims to its wa