Shop Baby's at RalphLauren.com, the Official Site of Ralph Lauren. Big Pony Trek Vest - This rugged, super-warm vest features a cozy downlike fill and our signature embroidered Big Pony at the chest. Mockneck. Full-zip front. Sleeveless silhouette. Vertical zip welt pockets at the waist. Even-sewn hem. Fully lined and filled. Our signature embroidered Big Pony accents the left chest. Shell and fill: 100% polyester. Lining: 100% nylon. Machine washable. Imported.