80/20 down fill means 80% down clusters and 20% feathers. Down provides a higher warmth-to-weight ratio than synthetic fill, it traps more heat with less material, which is why this vest stays slim rather than bulky. Synthetic insulation is typically used as a cheaper alternative; it holds warmth better when wet but doesn't match real down for loft or packability.

Fill power measures how much space one ounce of down occupies, the higher the number, the more loft and warmth per ounce. At 530 fill power, this vest sits in the mid-range: warmer than most vest-weight fills, and light enough to layer under a jacket on colder days. It's suited for temperatures where you need real warmth without the weight of a full jacket.

Yes. The shell is 100% full-grain genuine lambskin leather. Full-grain is the highest quality cut of leather it retains the natural grain of the hide and develops a patina with wear rather than degrading. It's a step above split-grain or bonded leather, which are commonly used in lower-cost leather garments.

The slim silhouette means it fits closer to the body than a traditional puffer vest. It's designed to layer over a shirt, sweater, or light hoodie without adding volume. The hem cinch toggles let you adjust the fit at the waist for a more tailored look. If you run between sizes or want room for a thicker underlayer, sizing up is recommended.

YKK is the global standard for high-quality zipper hardware used in premium apparel because their zippers consistently pass durability and smoothness tests that off-brand hardware fails. The antique brass finish adds a warm, vintage-toned detail that complements the black leather shell without looking flashy. It's the kind of hardware detail that becomes obvious when you handle the vest.