Authentic and in great used condition! I bought for some summer trips but no longer need it. I cannot see any marks or flaws beyond general wear. Size medium. Over $500 new. From Arc’teryx: Made for alpine travel and mountain realities, the Beta SL Jacket – our lightest Beta – is carefully designed to deliver complete waterproof, windproof, breathable protection without sacrificing features or packability. Its next-generation GORE-TEX ePE membrane is light, thin, strong, and PFC free. C-KNIT backer technology improves comfort and breathability. The helmet-compatible StormHood protects without compromising vision, pit zippers ventilate, and a RECCO reflector can aid in search situations.