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: Platinum Pets Medium Pinch Dog Collar Medium, 18-Inch, Bubblegum Pink
Product description: The platinum pets pinch collar is a great training collar for dogs. The prongs are rounded and have blunt ends to prevent injury to your pet. It features a durable and long lasting powder coating.
Product feature: Rounded, blunt prongs meet skin when collar tightens, Hand-welded heavy duty chrome plated links, Collar is finished in a Long lasting, extra durable powdercoat finish, Matching chain leash sold separately, Not for use with tie out
Product brand: Platinum Pets
Target attributes: Size
Answer: attribute: size
value: medium
source: product title