Instruction: Given the title, description, feature, price, and brand of a product and a set of target attributes, extract the value of each target attribute from the product information. Output the extracted value and the corresponding source (e.g., title or feature) denoting where the value is extracted.

Input:
Product title: BOSS AUDIO TW20 250-watt 1" Dome Tweeters
Product description: BOSS AUDIO TW20 250-watt 1" Dome Tweeters
Product feature: 1 inch Polyimide Dome Tweeter Pair, 250 Watts MAX Power Handling per Pair, Mounting: Surface, Angel, Swivel, 3 Year Platinum Dealer Warranty, Power handling, Peak 250 Watts; Magnet Structure, Strontium, Impedance, 4 ohm; Frequency Response, 5-20kHz, SPL 1 watt/1 meter; 102db; Type, Micro Dome, Mounting, Surf/Flush/Swivel; Mounting Kits, 3, Mounting Kits, 3
Product brand: BOSS Audio Systems
Target attributes: Channels
Answer: attribute: channels
value: None
source: None