Thermal underwear seamless base layer unisex long sleeve top is snug fitting & has plenty of stretch (100%) which makes it feel as comfortable as a second skin & allows for a close comfortable fit for most body shapes. The stretch, coupled with long cut, will prevent the garment from rucking up under active conditions that may cause discomfort & cold spots on the lower back. The super efficient hydrophilic finish will wick perspiration away, leaving your skin feeling warm & dry. The innovative seamless body construction incorporates stretch rib zones for enhanced support & waffle zones for increased thermal efficiency & greater control of perspiration. This is the ultimate in thermal underwear base layer technology & is suitable for all outdoor sports where extra warmth is required but without the bulk: Lightweight walking, climbing, skiing, & cycling. For extreme temperature use in conjunction with the Factor 2 range of mid layer thermal underwear. For a more detailed size chart please visit our technical information pages. *PLEASE NOTE: This garment is sub-standard & may have a fabric fault such as a pull, a dye/dirty mark, or a manufacture fault such as a missed stitch. Apart from that the product is produced exactly the same & will perform just as well as a first quality garment.