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: Sanus System VM1B VisionMount LCD Wall Mount
Product description: Patent pending SmoothLock tilt and swivel systemExtruded aluminum design for high-tech lookWeight capacity: 50 lbs.
Product feature: Accepts LCD TVs with 75mm or 100mm VESA standard mounting interface, Patent pending SmoothLock tilt and swivel system, Patent pending Virtual Axis tilt mechanism, Extruded aluminum design for high tech look, Wood Stud Installation Approved - 50lbs. Weight Limit
Product brand: Sanus
Target attributes: Maximum Screen Size
Answer: attribute: maximum screen size
value: None
source: None