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: Thecus N2520 2-Bay NAS Server
Product description: Intel Atom SoC CE5315 Dual Core (1.2GHz Dual Core ), 1GB DDR3, Intelligent NAS, Thecus OS6.
Product feature: 1.2 GHz Intel Atom CE5315, 1 GB DDR3, NA, Data guard, HDMI output, USB 3.0, Free DDNS, Intel Atom SoC CE5315 Dual Core (1.2GHz Dual Core ), 1GB DDR3
Product brand: Thecus
Target attributes: Type
Answer: attribute: type
value: nas server
source: product title
attribute: type
value: nas
source: product description