On days when the weather is not cold enough for a jacket, but is too cool or changeable to make a jersey with warmers and a vest practical, you need the Fly Jack-Sey. It offers weather protection and a touch of warmth but won't make you overheat.
The Fly Jack-Sey is so called because it makes use of the brand's latest innovation, Castelli FLY Fabric Technologies (FFT). This is a three-layer material with a windproof yet breathable Gore-Tex Infinium™ Windstopper® inner, then a mid-layer and outer made from 100% recycled material – the insulation being CLIMA SL, which is super light but also very warm, and the outer being FLY SL, which is windproof and treated to shed rain and spray.
The Gore-Tex Infinium™ is only found at the front, the portion of the vest most likely to encounter the elements, which means that the back of the jersey is cooler, lighter and allows a little more air circulation. The jersey also features a low/no collar cut, which is fitted to stop wind from rushing down the neck and making you chilly, but also allows more heat to escape.
This practical garment is finished like the best Castelli jerseys and jackets, with three back pockets and one zippered valuables pocket, reflective tabs for safety, a waist that stays put in ride position and a zipper that can be opened from the top or bottom, allowing easy venting mid-ride.
Unlike those other layers, though, it hits the sweet spot of keeping you warm and protected, without causing you to overheat, on days when both you and the weather can't make up your minds.
Features:- An incredibly light layer offering protection from the elements
- Cut with a low/no collar for improved temperature regulation
- With 3-layer Castelli FLY Fabric Technologies (FFT)
- Front of jersey features windproof, breathable Gore-Tex Infinium™ Windstopper® inner
- CLIMA SL insulation mid layer is 100% recycled post-consumer and adds warmth
- With FLY SL shell, also 100% recycled, for water shedding and wind protection
- Top and bottom opening YKK® Vislon® zipper
- With 3 good sized back pockets, zippered valuables pocket
- Elastic and silicone waist grips
- Reflective tabs aid safety in low light
- For a temperature range of 9-17°C
- Weighs 159g (M)