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: AllerEase Allergen Barrier Pillow Protectors – Waterproof Zippered Pillow Protectors, Allergist Recommended, Prevent Collection of Dust Mites and Other Allergens, King Sized, Set of 2
Product description: If you wake up every morning with a stuffy nose or congestion, it could be due to allergens in your pillows. With AllerEase allergen barrier pillow protectors, its easy to get a better, more restful nights sleep and wake up feeling refreshed! Our pillow protectors offer a complete allergen barrier protection to block common household allergens like dust mites, pollen, pet dander and more from settling in your pillows. The pillow covers are designed to help allergy and asthma sufferers who are sensitive to common triggers, and we combine superior filtration with waterproof protection for the ultimate in protection. Fully encasing your pillow with a durable and comfortable zippered and waterproof pillow protector not only protects against household allergens, it extends the life of your pillow, keeping it fresh and clean. These pillow protectors have a 220 thread count and are 100% polyester for a soft, smooth look and feel. Best of all, they are noiseless. This pillow cover set fits king sized pillows and are best used over a pillow with an additional pillowcase over them. AllerEase is the leading brand of allergen barrier bedding. All our products provide natural allergy relief, are allergist recommended and are tested by an independent 3rd party for durability and protection. Customer satisfaction is importance to us, that's why AllerEase offers a 10 YEAR LIMITED WARRANTY. We're confident you'll LOVE our products. IMPORTANT: This product is DISTRIBUTED IN THE USA in NEW CONDITION by the ALLEREASE brand ONLY. Check sold by Amazon to ensure authenticity.
Product feature: 100% Polyester, Imported, COMPLETE ALLERGEN PROTECTION: If you wake up congested, it could be allergens in your pillows. Our pillow protectors offer complete barrier protection, blocking dust mites, pet dander and other common household allergens., ALLERGIST RECOMMENDED: Our pillow covers are designed to help allergy and asthma sufferers who are sensitive to common triggers. We combine superior filtration with waterproof protection for the ultimate in protection., EXTEND PILLOW LIFE: Fully encasing your pillow with a durable and comfortable zippered protector not only protects against household allergens, it extends the life of your pillow, keeping it fresh and clean., PREMIUM QUALITY: These pillow protectors have a 220 thread count and are 100% polyester for a soft, smooth look and feel. Best of all, they are noiseless., LEADING BRAND OF ALLERGEN BARRIER BEDDING: All AllerEase products provide natural allergy relief, are allergist recommended, and have a 10-year limited warranty. Customer satisfaction is important to us.
Product price: $21.54
Product brand: Aller-Ease
Target attributes: Size
Answer: attribute: size
value: king sized
source: product description
attribute: size
value: king sized
source: product title