Buy from Amazon.com : http://best.waitmejapan.com/?asin=B0137ETT8O

12x12x1 Electrostatic Washable Permanent AC Furnace Air Filter Reusable Silver Frame

Product Description :
Traps 95 of airborne dust and allergens
Permanent Washable - Just hose off and reinstall
Replaces disposable furnace filters
Made in USA - Lifetime warranty
Self-charging electrostatic filter media - does not require electricity