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: Vic Firth American Classic Extreme 5B Nylon Tip (X5BN) Drumsticks
Product description: The American Classic line combines tradition and Vic Firth style. With bold designs for fuller sound, the Classics are turned from select hickory a dense wood with little flex for a more pronounced sound. Hickory is also capable of withstanding a great deal of shock, making it highly durable. The nylon tip is similar in size and shape to the Extreme 5B, providing enhanced performance and a feel closer to the original wood tip model. Nylon tips are the most durable and brightest sounding on cymbals. Length= 16 1/2 Diameter= .595
Product feature: Model X5BN, Length: 16.5", Diameter: 0.595", Like the 5B, with more power and reach
Product price: $13.43
Product brand: Vic Firth
Target attributes: Size
Answer: attribute: size
value: 5b
source: product title
attribute: size
value: 5b
source: product feature
attribute: size
value: 5b
source: product description