Our singlets are made by 2ndSkin and from Vaporlite fabric which is super light weight to wear, perfect for running or walking in hot conditions. The active moisture wicking attributes keeps you naturally cooled by increasing sweat evaporation. Vaporlite’s unique fabric has a distinctive soft feel against your skin, making it extremely comfortable. Sizing tip: The sizing chart is not a reference to your actual body shape, but the size of the shirt when laid flat so grab your favourite running shirt and measure it up to compare the sizes. Please see the sizing chart included in the images for more details. THESE ARE SLIM FIT SINGLETS SO IF YOU MAY PREFER TO GO UP A SIZE IF YOU LIKE A LOOSER FIT. A sizing chart can be viewed by clicking either arrow in the image.