Men's base layers are available in a range of weights to accommodate almost any climate. Ultra-Lightweight and Base Layers provide dry, cool comfort when the temperatures rise. Lightweight layers are great on days that start off a little chilly, but temperature could warm and vary throughout the day. Both ultra-lightweight and lightweight layers work as standalone pieces or as a moisture wicking barrier under your foul weather gear. Midweight and Heavyweight Base Layers have the moisture moving properties with added warmth. Thermal long johns, base layer tops, heavyweight long underwear and thermal tops all serve to suit your cold weather base layer needs.