Rooster has designed HOT TOP: a revolution of heat. It is made up of a 0.5mm layer that is both comfortable and warm. It is a garment to be worn under normal sailing equipment to have a greater supply of heat. Remember: The number of layers is more important than the thickness. Titanium neoprene works similar to a survival blanket: the titatnium impregnated layer reflects body heat and radiates it to the body. FIT NOTES: This garment should be worn tight to provide more warmth. Wear the sleeves up to the elbow and, once the HOT TOP is lined up along the arms, proceed to put it on. For better comfort, we recommend wearing the HOT TOP over a thermal BASE LAYER, such as the PolyPro Top.