Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Stainless Steel Celtic Claddagh Ring with Trinity Knots
Product description: High polish finish. . Antiqued detail. Ring measures 9mm long.
Product feature: Shipping Information: View shipping rates and policies, ASIN: B00GHXPMK2, Date first listed on Amazon: November 6, 2013, Average Customer Review: 5.0 out of 5 stars 12 customer reviews
Product price: $15.10
Product brand: 100Silver
Target attributes: Silhouette
Answer: attribute: silhouette
value: None
source: None