Features: Ideal for metal recyclers, brokers, antique buyers, collectors, or anyone that needs a convenient, easy-to-carry magnet to test for iron, nickel, or cobalt content. Identify fake or plated jewelry, which often has steel or nickel alloys as the base material (some alloys, like nickel-silver and German silver, are non-magnetic, despite having ferrous metals present). The magnet test is generally the first step, prior to density and acid testing. Helps identify and sort chrome-plated items from polished aluminum, silver, and non-magnetic grades of stainless steel (chrome plating typically includes a nickel layer, which is magnetic). Useful for identifying and sorting solid brass and bronze from steel-plated items (handy in the antique market and hardware stores). Specifications: Material: Iron Size: Base 1: Approx. 12mm / 0.47 inch (maximum pull-off force 4kg) Base 2: Approx. 15mm / 0.59 inch (maximum pull-off force 9kg) Base 3: Approx. 17mm / 0.66 inch (maximum pull-off force 13.5kg) Base 4: Approx. 21mm / 0.82 inch (maximum pull-off force 17kg) Shell plating: Nickel, Copper, Nickel Adsorption direction: Magnetism is located only at the bottom Use temperature: Do not expose to temperatures higher than 75 degrees Celsius Note: Please allow 1-2 cm errors due to manual measurement. Please ensure you are comfortable with this before ordering. Due to differences in monitor displays, the image may not reflect the actual color of the item. Package includes: 1 x Keyring magnet