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: Dell Latitude 13 Education Series 3340 (Certifed Refurbished)
Product description: Operating system Windows 8 Pro or Windows 7 Professional Flexible for Education Inspire students of all learning styles to do more with a powerful Intel 4th generation processor, a large 13.3 HD (1366 x 768) display, and easy connection to classroom projectors, cameras or other devices. Choose the optional touch screenlaptop for a truly interactive experience and a new way to engage with content. Support learning in and out of the classroom with seamless access to offline software-based educational programs and cloud-based content. Enable creativity while monitoring students with an activity light that indicates if they are on the network and shouldnt be. Keep learning from the first bell to the last with the long-lasting that stays charged up to 13 hours. Durable by Design Take the hard knocks of school and keep on going with superior shock absorption provided by the rubberized LCD trim and an SSD with no spinning parts. The Latitude 13 Education Series can handle it all. Work without worrying about spills. The exclusive sealed keyboard and touchpad provides the industrys best protection against spills on a student laptop. For easy collaboration, students can use the 180-degree hinge to lay the screen completely flat without worrying about it breakingits been tested for student wear and tear. Get outstanding scratch-resistant protection with the optional 13" touch screen designed for exceptional durability and vivid color. Choose accessories to complete the classroom
Product feature: Intel Celeron 2957U Processor 1.4GHz, 500GB Hard Drive and 4GB RAM, 13.3-inch Screen (1366x768) With Intel HD Graphics, Windows 8, No Optical Drive.
Product brand: Dell
Target attributes: Refresh Rate
Answer: attribute: refresh rate
value: None
source: None