Description The Sitka Grindstone GTX Jacket is a rugged insulated work layer designed for demanding cold and windy conditions. PrimaLoftA(R) Silver insulation provides dependable warmth, while WINDSTOPPERA(R) by GORE-TEX LABS blocks wind to help maintain comfort during long days outside. A highly durable Gore and CorduraA(R) laminated fabric adds abrasion resistance for jobsite, ranch, and field use. Sizing Size Chest Sleeve Medium 39" - 41" 34" Large 42" - 45" 35" Large Tall 42" - 45" 37" X-Large 46" - 49" 36" X-Large Tall 46" - 49" 38" XX-Large 50" - 53" 37" XXX-Large 54" - 57" 38" How to Measure: Chest Measure around the fullest part of your chest, keeping the tape under your arms and across your shoulder blades. Sleeve Bend your elbow and place your hand on your hip. Measure from the center back of your neck, across your shoulder, down your arm, over the elbow, and to the wrist bone. Specs Material 100% Nylon Cordura Oxford fabric Wind Proof Yes Insulation 100 grams PrimaLoft Silver synthetic Manufacturer Warranty Lifetime against manufacturer defects