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: FOREVER DELLA-80 Women's Sleek Vamp Stiletto Heel Platform Knee High Boots, Color:BLACK, Size:7.5
Product feature: Importado, Package Dimensions: 10.5 x 10 x 5 inches, Shipping Weight: 2.45 pounds, ASIN: B00NWGPPY0, Item model number: DELLA-80, Date first listed on Amazon: March 3, 2016, Average Customer Review: 5.0 out of 5 stars 1 customer review
Product brand: Forever
Target attributes: Silhouette
Answer: attribute: silhouette
value: stiletto
source: product title