Instruction: Extract the value of the target attribute from the given product information and output it along with the corresponding source.

Input:
Product title: Smith Bridgetown Carbonic Polarized Sunglasses
Product description: Smith Optics Bridgetown polarized sunglasses. Round frame. Metal bridge detail. ChromaPop#8482; polarized lenses. Barrel hinges. Hydrophilic megol nose pads. 6 base lens curvature. Evolve frame material - made from easily renewable non-GMO castor plants. Imported. Vendor style #: BNPPBRGMB.
Product feature: Carbonic Polarized lenses, Medium fit/large coverage, Auto-lock hinges, Hydrophilic Megol nose pads, and evolve frame material, 6 base lens Curvature
Product price: $84.93
Product brand: Smith Optics
Target attributes: Silhouette
Answer: attribute: silhouette
value: round frame
source: product description