arm warmers -
Castelli Thermoflex Arm Warmers - seems to be the go to ones? Anyone got them, sizing etc??
I have the Thermoflex arm (& knee) warmers and am impressed by them. They do have a very fine fleece like lining which is lovely in very chilly weather but be warned in milder weather whilst they aren't prone to causing overheating they do mask just how much you might be sweating very well.
Size large fits a 16" bicep snuggly, no idea how long my arms are but at 5'10" I'm not gangly and have an inch or two to play with under the jersey sleeve.