David Millar says:
"Don't Leave Home Without One - That's what we call these in the
UK. Well, that's what I used to call them till I became a cyclist
and started calling them gilets. One of the first rules I learnt as
a pro was to never leave home without one; it was as important as
spare tubes and a multi-tool.The 1.71 Body Warmer does what it says
in the name while feeling nearly weightless due to the materials
FRONT - 70g/m2 eVent windproof breathable fabric, the same used
in the 1.41 K61 Rain Jacket.
BACK - Highly water-repellent stretch woven fabric, the same
material used to make the magic swimsuits that smashed world
records (in other words, water will be rolling off your back like
the proverbial duck's).
The combination of these two materials means protection and
warmth on the front and enough breathability on the back to let the
sweat out while being nearly waterproof throughout. There is an 8cm
collar, as my experience has shown that a high neck simply makes
you feel more protected and warmer, and two pockets on the back, as
sometimes you're forced to wear it for longer than anticipated and
it's good to have access to supplies if needed, although because of
the minimal construction you'll want to keep heavier stuff in the
inside jersey pockets. Like the 1.21 Jersey with its understated
look, it is designed to last longer than fashions.
The 1.71 Bodywarmer will become an essential part of your
cycling life for years to come. Make the middle back pocket of your
jersey its home."