The Black Diamond Heavyweight Wool Liner gloves pair a merino wool and polyester blend that keeps insulating even after it's wet, so a mid-hike sweat or a wet snowfall doesn't undercut the whole point of wearing a liner. Reinforced palms and a touchscreen-ready thumb and index finger keep everyday tasks glove-on, whether the liners work alone in mild cold or slide under a shell glove when temperatures drop further. What Our Gearhead(R) Experts Are Saying:"I got these soaked wading a creek crossing on a shoulder-season hike, and they still kept my hands functional instead of clammy and cold. Wool holds onto warmth wet in a way synthetic liners just don't, so I'm not stopping to swap gloves the second conditions turn."