Helen's Asian Kitchen Pre-Seasoned Carbon Steel Wok is crafted from heavyweight 1.8-millimeter carbon steel that's been nitrogen-treated for a natural, chemical-free and highly durable non-stick surface. It's safe for use on gas, electric, open flame, induction, and ceramic cooktops for stir frying, sauteing, steaming, braising, frying, and deep frying. Metal tools and scrubbers will not damage or remove the pre-seasoned surface. Nitrogen treatment is a natural, chemical-free process performed at over 1000-degrees Fahrenheit for a non-stick surface with unprecedented durability. Hand wash in warm, soapy water and dry thoroughly. Brought to you by HIC, a third-generation family owned and operated company in the USA since 1957.