Instruction: Using the product's title, description, features, price, and brand, identify and retrieve the values associated with a specified set of target attributes. Output the extracted values along with their respective sources (e.g., title or feature) indicating where each value was found.

Input:
Product title: Mb Quart Rlp304 12 600w 4 Ohm Car Audio Subwoofer Sub 600 Watt Rlp-304
Product description: Description:, 12" Dual 4 Ohm Reference Series Shallow Mount Subwoofer Power Handling: Peak: 600 watts RMS: 300 watts Impedance: Dual 4 Ohm Shallow mount for small and compact installations Injection molded polypropylene cone woofer Recommended use in sealed enclosures Dual voice coils Foam surround Frequency response: 25-160 Hz Sensitivity: 86 dB
Product feature: New - Retail, 30-Day Warranty, MB Quart rlp304, Mb Quart Rlp304 12 600w 4 Ohm Car Audio Subwoofer Sub 600 Watt Rlp-304
Product brand: MBQUAR
Target attributes: Impedance
Answer: attribute: impedance
value: 4 ohm
source: product feature
attribute: impedance
value: 4 ohm
source: product title
attribute: impedance
value: 4 ohm
source: product description