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: Gigabyte AMD Radeon R9 290 4GB GDDR5 2DVI/HDMI/DisplayPort PCI-Express Video Card GV-R929WF3-4GD
Product description: WINDFORCE 3X 450W cooling system; Powered by AMD Radeon R9 290 GPU; Integrated with 4GB GDDR5 memory, 512-bit memory interface; Features DVI-Dx2 / HDMI / DisplayPort; Core Clock: 947 MHz; System power supply requirement: 600W
Product feature: GIGABYTE GV-R929WF3-4GD AMD Radeon R9 290, Core Clock: 947 MHz, 4GB GDDR5 2DVI/HDMI/DisplayPort PCI-Express Video Card, Memory Interface:512-bit, Bus:PCI-Express 3.0, Max. Resolution:4096 x 2160
Product brand: Gigabyte
Target attributes: Power Connectors
Answer: attribute: power connectors
value: None
source: None