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: Top Knobs M363 Somerset Collection 3" Cup Pull, Black Iron
Product description: Somerset Cup Pull 3" (c-c) - Black Iron, Finish:Black Iron A traditional brass cup pull available in 10 finishes to match your color scheme.
Product feature: Center to Center: 3" (76mm), Overall Length: 4-5/8" (117mm), Projection: 15/16" (24mm), Width: 1-7/16 (37mm), Traditional / Classic Style
Product price: $13.77
Product brand: Top Knobs
Target attributes: Finish
Answer: attribute: finish
value: None
source: None