Magnetic Material Sheet 4 x 12-inch (.030 in. thick) Black Thin & Flexible for Magnetizing Bumper Sticker Flexible magnetic material black on both sides. 4 x 12 x .030 inch Clings to any steel surface Very thin., .75 mm, about 1/2 as thick as a penny. Please purchase from Lifeweaver LLC to assure item is not an inferior counterfeit.