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: Precision Power BI.104 450W 10" Black Ice Series Dual 2 Ohm Subwoofer-Set of 1
Product description: 450W 10" Black Ice Series Dual 2 Ohm Subwoofer. Sensitivity: 87dB. Top-mount depth: 5-3/8". Resonance Frequency (Fs): 33 Hz. 2" 4-Layer voice coil on aluminum former.
Product feature: 10" Dual 4 Ohm Black Ice Series Subwoofer, Power Handling: RMS: 450 watts, Non pressed paper pulp cone, High roll foam surround, Poly-cotton suspension spiders
Product brand: Precision Power
Target attributes: Amplification Type
Answer: attribute: amplification type
value: None
source: None