Material and build - Made of stainless steel with a satin finish for durability and smooth operation. The design is robust, provides even performance, and fits your needs. A protective case is included to shield the tool from damage. Calipers and measurement capability - Premium gold calipers are curved for accurate measurements. Measures the Golden Mean, also known as the Golden Ratio 1:1.618. Suitable for biology, art and mathematics students, artists, tattoo artists, shell makers, and architects. Eyebrow sizing and beauty applications - This caliper is commonly used for eyebrow sizing, offering greater precision during the initial phase of permanent facial makeup. It is widely used in microblading and other beauty practices. Portability and convenience - Golden Ratio eyebrow ruler is portable and easy to carry in your cosmetic bag or handbag. use scenarios - Brow design and symmetry in microblading or permanent makeup to plan and execute precise eyebrow shapes. - Educational or professional design work in art, architecture, mathematics, biology, or shell crafting that incorporates the Golden Ratio 1:1.618. - On-the-go measurements for beauty professionals, travelers, or field applications where precise sizing is needed.