Building off the legendary versatility of the Atom LT Hooded Jacket, the Arc’teryx Men’s Atom SL Hooded Insulated Jacket retains the LT’s multi-use functionality, all while shaving 20-grams of Coreloft insulation to achieve a lightweight layering piece that’s ideal for summer adventures. In fact, you’ll find the Atom SL Hooded Insulated Jacket saves approximately 3. 5-ounces over the LT, making it better suited for lightweight alpine hikes and minimalist peak-bagging missions in the summertime. Coreloft Compact 40 synthetic insulation retains body heat on those chilly summer mornings and evenings. This insulation is highly compressible, lending itself to easy storage within your pack.