works great under a snow jacket for superior warmth- works great as a layering piece - snug fit Exceptionally warm, directionally knit Polartec® Thermal Pro® fabric is breathable, compressible, wicks moisture and dries quickly Side panels, sleeves and cuffs feature R1® Polartec® Power Grid™ for improved fit and breathability Technical fit, underarm gussets and raglan sleeves for increased mobility and comfort under outerwear and packs zippers have Sonic/Stitch seam construction to reduce bulk Length is 28"; Width is 22"; Sleeve is 33"