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: Elkay Lustertone MYSTIC3021BG Single Bowl Undermount Stainless Steel Sink Kit
Product description: An Elkay Lustertone sink looks as great on day 3,000 as it does on day one. Our signature finish is handcrafted with a rich, uniform grain that adds to the beauty of the sink. Light scratches, which occur with everyday use, naturally blend into the finish with time.
Product feature: LUSTERTONE FINISH: Durable, handcrafted finish looks as great on day 3,000 as on day one. Light scratches naturally blend into sink finish with time, UNDERMOUNT INSTALLATION: Sink is installed beneath the countertop creating a seamless appearance between the sink and the countertop, SINGLE BOWL: Bowl gives you uninterrupted space for washing and stacking dishes or other household tasks, 18-GAUGE STAINLESS STEEL: Highest quality 18-gauge thickness and Type 304 stainless steel for lasting durability, performance and lustrous beauty, QUIET: Sound-deadening pad(s) minimizes sound and vibration for a quieter time at the sink, OFFSET DRAIN: Drain placement provides more usable space on the bottom of the sink and in the cabinet below, REMOVABLE SHELF: Sturdy, stainless steel shelf is ideal for drying dishes; remove shelf for access to entire sink
Product brand: Elkay
Target attributes: Material
Answer: attribute: material
value: stainless steel
source: product feature
attribute: material
value: stainless
source: product feature
attribute: material
value: stainless steel
source: product title