Weights are physical measuring tools in the mass measurement transmission system, used for calibration of scales and apparatus, as well as industrial process quality control. The top knob/bottom screw is closed, making it easy to fine tune the quality after periodic calibration. Magnetic tweezers/gloves: Avoid hand contamination and magnetic interference. Application scenarios: Metrology institutions: Establishing national quality benchmark chains for pharmaceutical/food companies; Jewelry/precious metals: rapid traceability of carat balance and specific gravity balance; Port/logistics: on-site inspection of weighing scales and track scales, equipped with aluminum alloy forklift handling frames; Teaching demonstration of physics, chemistry, and quality measurement.