The Rapha insulated gilet is perfect for those days when you need an extra later but don't need a jacket. Think autumnal morning before the sun's warmth arrives. It will fit in most jersey pockets when you decide you are warm enough to take it off. (In case anyone isn't familiar with a gilet, it is a light jacket but without any sleeves.)
I found that I didn't wear a gilet as often as I expected. It's therefore in very good condition, with just a couple of marks that are barely noticeable. It doesn't have any pockets.
It has a reflective strip across the whole gilet. Combined with the bright yellow colour, you will be reassuringly visible.