David Millar says:
"The colour has been chosen to interchange with both colourways
of the 1.11 short and 1.21 jerseys. The material is Castelli's
Thermoflex fabric, a step up from the Roubaix fabric that most
companies use.It has a slightly tighter knit with higher loft
fleece that happens to be more stretchy. This is useful to
cyclists, as we often have to make contortionist moves when
searching around to get into our jersey's rear pockets. Or lift a
coffee to our mouth. Or reach down to pull our socks up. Or adjust
our shoes. That sort of thing.
There is elastic at the top to hold them in place, and a
turnable cuff with the Rosso Fuoco reveal and a reflective stripe
at the bottom (our little attempt to help those times you get stuck
too long in a café and have to race home before it gets dark).
Arm warmers are a little easier to take on/off than knee-leg
warmers. Just pull them on or off; try and align the seam so that
it runs right through your elbow in a straight line. And please,
make sure there is no skin showing between the sleeve of your 1.21
jersey and the top of your 1.91 arm warmer."