Material: Made of plastic and metal, the metal hook is not easy to break, can measure objects repeatedly, and is durable. Convenient to carry: The manual scale has a spring at the l 'inside and a scale line is engraved on the outside. The scale is clear and the measurement is precise. There is a hook at the bottom. It's something you can take with you when you travel. Practical tool: It can be a school teaching tool to engage students and explore cognition, or it can be a act as a small accessory for measuring the weight of small objects at home. The operation is simple and easy to understand: The balance has two forms of calibration: Gram and Newton Simply hang the measuring object on the hook, place it vertically, and see what scale value the spring stops at, you can quickly determine the measuring object. Packing: A set of 2 packs, Spring Balance Scales, 5N, can measure weights up to 500g.