Description ***GOHUNT Staff recommends ordering this true to size if worn as a mid-layer over a shirt or lightweight hoody. You might need to size up if you want to wear this over a large jacket or puffy.*** The Outdoor Research Helium UL Jacket delivers ultralight waterproof protection for fast-moving days on the trail, travel, and everyday use. Toray Dermizax(TM) 3D 2.75-layer construction improves breathability, comfort, and durability while fully taped seams and YKKA(R) AquaguardA(R) zippers help seal out wind and rain. An adjustable wire-brim hood, shaped cuffs, and a chest pocket that doubles as a stuff sack keep the design streamlined, packable, and ready for changing weather. Sizing Medium Large X-Large XX-Large Chest 38.5"-41.5" 41.5"-44.5" 44.5"-48" 48"-52" Waist 31.5"-34.5" 34.5"-37.5" 37.5"-41.5" 41.5"-45.5" Hips 37.5"-40.5" 40.5"-43.5" 43.5"-46" 46"-49.5" Sleeve Length 33.5" 34.5" 35.5" 36" How to Measure: Chest Measure around the fullest part of your chest, keeping the tape parallel to the floor and positioned under your arms. Arm With your hand on your hip, measure from the center of the back of your neck, across the shoulder to the elbow, and down to the outer wrist bone. Hips Measure around the fullest part of your hips, keeping the tape parallel to the floor. Sleeve Length With your arm relaxed and slightly bent, measure from the center back of your neck, across your shoulder and elbow, down to your wrist. Specs Weight 5.7 oz Material Toray Dermizax 2.75L 100% Nylon 15D Ripstop 61 G/M2 Shell Manufacturer Warranty Lifetime guarantee