The Arcteryx Phase AR Zip Neck is a superb base layer shirt that is lightly insulated with fantastic wicking properties. The letters “AR” refers to this garments all round ability to perform across a wide range of temperatures & conditions. Phase fabric technology is designed to perform superbly during stop & go activities, regulating your body temperature by retaining less moisture & drying faster. When you are active & sweaty moisture is wicked across the whole garment, keeping you comfortable. When you stop that dispersed moisture evaporates quickly, keeping you drier, warmer & more comfortable. Lighter weight & quicker drying panels of Phasic SL fabric are located under the arms to reduce bulk & improve thermal regulation & the zipped neck acts to enhance ventilation. Silver-ions encapsulated in all the fabric to reduce odour. The Phase AR is also supremely comfortable due to its mechanical stretch & great anatomical shape with no nasty chaffing seams or bulky neck & cuffs. Arcteryx perfection for your body. Moisture-wicking Breathable Lightweight ultra quick-drying Minimal odour retention Odour-control fabric treatment Hydrophobic materials will not absorb water Mechanical stretch textile for unrestricted mobility Flatlock construction improves next-to-skin comfort Anatomical shaping for fit & comfort Gusseted underarms Laminated chin guard Quick-pull 1/2 length zip for easy venting Long sleeves Non-chafing label