Vinyl Replacement Windows Made in Maine. A-BEST windows are Envirosealed™ with Dura Platform spacers which reduces energy consumption, can save you up to $200 a year in energy costs, and reduces harmful CO2 emissions to produce a greener future. A-BEST Window utilizes the highest quality materials, workmanship and customer service to produce a product that's affordable and professionally constructed. We are a Maine company that manufactures, sells and installs replacement windows. Family owned and operated since 1985, A-BEST has an impeccable track record of hundreds of thousands of installations. At A-BEST we install your windows as if we were installing them in our own home.