Merino wool is the new alternative to be used in wetsuits and other thermo lined products. The reason for this development is that it comes from a sustainable resource whereas synthetic linings are constructed from petrochemicals. In addition, Merino is as natural and organic as your own skin. Being in the cold has never been this warm due to revolutionary, comfortable, antibacterial and odor resistant wool in your gear. In tests conducted by the British Textile Technology group, Merino lining proved to offer a 35% increase in thermal efficiency, in both dry and saturated conditions over the best, comparable synthetic linings.