Aluminum Folding Fan Diamond Karat Gemstone Mounting Gauge Measuring Carat Millimeters Gemologist Bead Jewelry Tools Feature: Great pocket gauge for measuring stones Portable folding fan-shaped gem size and diameter measuring tool, made of aluminum material, light quality, easy to store. You can choose from many styles: 6 arms fan-shaped, 8 arms fan-shaped, and 6pcs round shape . Suitable for measuring the diameter of diamond, gem and agate beads. With professional size scale on the surface, it is a very practical tool for jewelers and jewelers. With the help of this sizing gauge ,you will get a fast way to calculate the size and weight of a diamond. Specification: Material : Aluminum Color:Silver Size Chart: A 6 arms fan gauge hole size : 1-6mm ,length 55mm B 8 arms fan gauge hole size : 1-10mm.length 55mm C round fan shape : square size hole size 2-4mm round hole size approx 1-10mm Quantity:1 Pc. Note: Size for manual measurement, there may be a 0 to 3mm error, belongs to the normal phenomenon. And due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 set diamond fan gauge