Guardian TECHNICAL Mens Merino Thermal Underwear Long Johns Pants. Nature at it's best..... Wearing our merino helps you stay comfortable on your adventure - NO more itching, NO more odours. Fabric Technology - Guardian has developed an innovative new fabric by fusing superfine Australian merino wool and a technical heat generation yarn together. The heat generation yarn is made from micro-fine fibers which is super light and soft with insulating properties. When worn the wool layer generates heat from the body, while the the heat generation yarn traps heat in. The fabric retains its antimicrobial properties for many washes - keeping those odour causing bacteria at bay. It truly is better than being naked ! Body fit finishing to give the highest level of comfort. Machine Washable and quick drying.