Light, packable all-mountain GORE-TEX ePE shell with an extensive feature set. *The Beta SL Jacket was previously the Beta Lightweight Jacket. The Beta SL Jacket – Arc'teryx lightest Beta – is built for mountain realities. Highly versatile, it's carefully designed to deliver complete waterproof, windproof, breathable protection without sacrificing lightweight packability. Its innovative GORE-TEX ePE membrane is light, 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.