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: Original Penguin Men's Circle Logo Tank Top
Product description: Classic penguin Pete graphic circle logo crewneck tank top
Product feature: 100% Cotton, Imported, Machine Wash, Penguin logo, Heritage slim fit, Package Dimensions: 6.8 x 5.3 x 1.1 inches, Shipping Weight: 1.6 ounces, ASIN: B0182UVULW, Item model number: OPKS6312, Date first listed on Amazon: January 9, 2016, Average Customer Review: 4.5 out of 5 stars 2 customer reviews
Target attributes: Neckline
Answer: attribute: neckline
value: crewneck
source: product description