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: Sunpak CF-7060 CP Circular Polarized Filters 62mm
Product description: Increases color saturation and contrast by reducing reflections from non-metallic surfaces and by cutting through haze Deepens sky color. Generally requires throught-the-lens viewing.
Product feature: Filter_Type - Polarizer, Filter_Attachment_Diameter - 62 mm, Compatibility - Camcorders, Manufacturer - Tocad America, Inc
Product brand: Slik
Target attributes: Shape
Answer: attribute: shape
value: circular
source: product title