The Craft Zero Extreme Concept base layer is like that old English Leather ad: "My men wear English Leather Zero Extreme, or nothing at all."
The Concept piece weighs in at 3.4 ounces. it feels wispy when you put it on, and then you basically forget you're wearing anything. It's stretchy and ultra-thin: the silver areas are a tighter weave, and the white areas are a meshy grid pattern that Craft calls Moving Wing technology. Basically the areas around the upper back, shoulders and lats are cut and faced differently to eliminate any pulling of the fabric.
The entire piece conforms perfectly to your skin, getting to all those hard-to-wick places. You know where they are. All seams are flat and the material is treated with an antimicrobial funk-slaying miracle juice distilled from baby eels found only at the bottom of the Marianas Trench. Bottom line, the Concept base layer wicks like Bounty paper towels and is the closest you'll come to wearing nothing at all. The price will likely give you nosebleed, but one gets the sense the target market is competitive athletes who are always willing to pay more for less.