The Cosmo is a high-neck maxi dress with a full, flowing skirt and ruched sides. Fully lined and fully flattering. The Cosmo is a high-neck maxi dress with a full, flowing skirt and ruched sides. Fully lined and fully flattering. Rails has been on a mission to redefine wardrobe staples, raising the bar for comfort and style in the industry. What began with a single plaid buttondown that felt softer than anything on the market, has evolved into a full range of lifestyle staples. With fabric innovation and the tactile experience at the heart of each collection, Rails continues to elevate essentials with timeless silhouettes and unmatched hand-feel — creating a brand that captures the essence of West Coast style from a global perspective.