Craftsmanship: This product is meticulously crafted with attention to every detail. The gemstones firmly secured by the pressure between the glass lid and the sponge Please do not open the lid. Careful Handling: If you must open the lid, please do so with caution. Open the very small angle and gently tap the stones adhered to the lid with tweezers to prevent them from falling out due to gravity. High Quality Iron Box: The product comes with a high quality iron box with a lid, ensuring the safety and integrity of the gemstones. Educational Tool: This product can be used to compare the size of diamonds, making it an excellent teaching and display tool. Material and Size: The product is made of iron and measures 20cmx5cmx1.6cm/7.87inchx1.97inchx0.63inch, making it compact and easy to handle. Size Chart: 20cmx5cmx1.6cm/7.87inchx1.97inchx0.63inch Package Includes: 1x Diamond Color Scale Stones Note: Please allow slightly errors due to manual measurement and different monitors.