This is called a J/J for a reason - modern fabric technology has allowed us to create a garment that can neither be defined as a long sleeve jersey or a jacket. In the past a long sleeve jersey would have a fairly small operational temperature range, often needing layering underneath or over the top to handle fluctuating conditions. A jacket has a different problem, more often than not it would end up being too hot under effort. The Jersey/Jacket can be considered both a jersey and a jacket, being able to handle a large temperature range thanks to the material used. A 3-ply of fabrics are bonded together around a foam core. That core not only gives the J/J its performance advantage but the unique look - there is nothing else like it out there.
"With the look of a 1980's diving jacket modelled on Sean Connery, the J/J is an instant talking point in the cafe. This is a really cool bit of kit and excellent intermediate jacket."
- Stuart Clapp, Rouleur Desire Editor
The performance advantage is due to the fact the foam wicks the sweat away from the body while also providing wind protection without compromising the breathability, this is why it can handle such varying conditions. The piping around all the seams is there for performance reasons as it prevents the three fabrics separating at the edges where it has been cut, although there were purely practical reasons for this it has also added to the overall look of the J/J.
The cut of the J/J is more like a jersey than a jacket, allowing it to be more fitted than a jacket normally would be, there are three rear pockets and also a vertical chest pocket with a zipper closure. The zip for this pocket and the main zip are quite chunky yet lightweight, it made sense to have a zip that had a bit more presence than normal in order to fit with the aesthetic. The neckline is slightly higher than a jersey, more like a jacket, everything about this garment is difficult to define apart from the performance, which has created its own definition the Jersey/Jacket.
CHPT3 bespoke clothing uses a tailoring system for its sizes. We use the physical chest or waist size as the garment size - If you have a 40" chest you need a 40" Jersey - Please note while the CHPT3 range is not designed for racing it is still a close-fitting athletic design suitable for active cyclists.
This is supposed to fit you to your actual size, no complications, measure yourself as below and that will work.