Castelli Emergency Rain Jacket

The Emergency Rain Jacket gives you a waterproof rating of 10,000 mm rating, an industry test where a 1inch diameter tube is placed over the fabric and filled with water until it starts leaking through; the higher the water (here, 10m), the more waterproof the fabric is.

A cycling jacket that resists light rain and showers extremely well. It's not designed for an all-day rain ride but it's just right for stowing in a jersey pocket for those emergency situations. The only real compromise compared to Castelli's top-of-the-line offerings is in breathability but that's not so key for a passing shower. 

The fit, as with all Castelli garments, is refined and tuned to be just right when on the bike. It's close to lessen flapping but it's still roomy enough to slip on over your Gabba, the slight amount of fabric stretch helping you to layer underneath.

For your riding days when you're just not sure if you'll get hit by a heavy shower, this jacket is easily stowed in a pocket just in case. It's so light and easy to stow there's no reason not to take it with you.