A. Material: Zinc alloy B. A Size: Length: 3.8cm, diameter: 1.8cm, with an error of approximately 1cm. C. B Size: Lock core length: 3.2cm, diameter: 2.5cm, iron plate length and width: 4.5 * 1.5cm, hexagonal length and width: 2.5 * 2.5cm, with an error of about 1cm. D. C Size: Total length: 13.8cm, with an error of approximately 1cm. E. D Size: Diameter: 4cm, height: 3cm, length and width of iron sheet: 5.5 * 1.8cm, with an error of about 1cm. F. Conversion: 1 inch = 2.54cm, 1cm = 0.393 inches G. Warm Tip: Please note that due to lighting effects, monitor's brightness/contrast settings etc, there may be some slight differences in the color tone of the website's photo and the actual item. H. Item measured by hand, there could be a 1cm difference. Your understanding is appreciated.