Gator Hot Noggen
Keep your head warm & dry with the Gator Hot Noggen Neoprene Helmet Liner! This fleece lined neoprene helmet liner completely covers the ears and is contour fitted to the head. It fits easily under cycling, motorcycle, and padded sports helmets. Serves well in industrial use under hard hats as well.
This thing is warm. Good price too!
This under-helmet hat kept me riding in the sub-freezing temps last winter. It is completely waterproof and nice and warm. Be aware that it does not breathe, so you may sweat under the hat. But the sweating didn't end up making me cold, because it's stuck under the hat and can't evaporate, so you stay warm and sweaty. 11 degree F days with sleet/ice/snow didn't faze me one bit with this hat and the booties and some good gloves. Nice to have the gear to ride year-round.