The Swix RACE X W top with long sleeves is part of the award-winning RaceX limited edition. The staple fibres have been replaced with infinitely long fibres for an even lighter and silkier feel. If you are looking for winter insulation, this is not a good choice. However, if you need thin, quick-drying underwear for added insulation during high-intensity training that will not overheat you, you are at the right place! Similarly to its older version, this underwear is super light, highly breathable and you can hardly feel it when wearing it.