Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Kenko 67mm L41 Super PRO WIDE Super-Multi-Coated Slim Frame Camera Lens Filters
Product description: L-41 is sharp-cut UV filters that blocks 90% of UV light below 410nm with almost no color tint.
Product feature: Normal UV glass has a slight yellow color tint, but the L-41 has none., Kenko recommends this filters for use in the mountains, at the beach, in areas of snow, and any other situations where there is a lot of UV light.
Product price: $19.90
Product brand: Kenko
Target attributes: Neutral Density Type
Answer: attribute: neutral density type
value: None
source: None