This Knox Cold Mid-Layer Jacket is one of the warmest pieces of thermal clothing I’ve used and is versatile enough that it is useful for three seasons, despite bring branded as winter kit.
Designed primarily to go under a winter jacket, it gives an added layer of warmth and wind protection on wintry days, but in the spring is also very useful under a leather jacket. In fact, I’ve also found its waterproofing capability to be very good, keeping me dry in a rainstorm when my over-jacket leaked.
Sadly it’s not really stretchy enough to go over leathers (unlike my Oxford Chill Out jacket) but looks good enough to be used as a normal jacket in real life, unlike the Oxford. I’ve also used mine when hiking and mountain biking as well. It’s good kit and well put together.