At the heart of this set is the multi-use mandrel, carefully crafted from high-quality hardthat provides the perfect balance of sturdiness and smoothness. The hard construction ensures the mandrel won't bend or warp with regular use, unlike plastic alternatives that can distort measurements over time. Its smooth surface, finished with a clear protective lacquer, allows jewelry to slide easily without catching or scratching delicate materials—critical when working with polished metals, soft leathers, or beaded pieces that could snag on rough surfaces.The mandrel's clear size markings are precision-printed and sealed under the lacquer finish, ensuring they remain legible even after years of use. The ring sizing section (US sizes 1-15) features clear increments that make it easy to identify the exact size of existing or determine the correct size for new creations. The bracelet measuring section (6-10 inches) includes both inch measurements and corresponding circumference markers, allowing you to work in your preferred unit of measurement for consistent results.The included adhesive tape adds significant convenience to the measuring process, especially for bracelets that might slip on the smooth mandrel surface. This specialized non-residue tape is designed to hold jewelry securely in place without leaving sticky marks or damaging delicate materials—a common issue with regular tape that can ruin finished pieces. The 10-yard length ensures you'll have plenty of tape for numerous projects, and its narrow 0.5-inch width makes it easy to apply precisely where needed without overlapping onto jewelry surfaces.For jewelry makers, accurate sizing is crucial to creating pieces that customers will love and wear regularly.