This copper sheet is 18 gauge or 40 Mil (.040 inches) thick and twelve inches wide by twenty feet long. It is manufactured to ASTM-B152 specifications, is annealed (soft and very malleable) with a smooth commercial finish, and is 99.9% pure copper alloy 110 . This sheet can be used for various craft and art projects, do it yourself and construction projects, electrical applications, manufacturing, and much more! It is shipped in foam packaging for superior protection during transit to ensure delivery without damage. If you have any questions, please don't hesitate to contact us via phone at 252-491-2812, via email at info@basiccopper.com or through our "live chat" and we will be happy to discuss your project!