The wool mattress pad is 1/2" thick, and is perfect for year-round comfort. The wool within is washable, and encased in 100% Natural Cotton (270 TC Percale). The pad naturally breathes easier than down, and synthetic, products. When properly cared for, it can last for decades. In general, wool out-performs other fibers used for bedding. The fibers quickly wick away moisture without making you feel cold, or clammy. This allows for less time spent tossing and turning. And all of this comes in eco-friendly re-usable packaging.